How are the mice getting in?

[kk7ds]

My wife has a beautiful 2006 E85 SI roadster. It's so beautiful that the mice love it too.

We store it in a self-storage unit during the winter right next to my E46 M3. We have glue traps lining the walls and don't leave any food (or really anything) in or near the cars. Yet, for the second time, we went to get the Z4 out only to find evidence of mice inside.

Unfortunately, this year, it was way worse. The glove box was their toilet, and they built a nest under the radio (behind the controls for the top and heated seats) with at least 10 live baby mice inside. It was awful. We're hoping that with all the bleach spray and ozone treatments we'll be able to get the smell out. It's a work in progress and most of the interior is disassembled while we do that.

HOWEVER, especially while it's disassembled, I'm trying to figure out how they're getting in and/or why they like the Z4 more than the M3 (I'm grateful, but my wife is not). I've got the full glove box area disassembled and the fuse box dropped down. I don't really see any obvious places (I know mice don't need obvious places) where they might be getting in.

Does anyone know of any design issues or obvious passageways that might be a thing we can plug up, even if just while winterizing? Any suggestions appreciated!

[HTM101]

We have mice get into our home periodically. From what I've read they can squeeze into a hole nearly as small as a pencil, so I doubt you can stop entry.

I copied this from a Terminix statement.

Mice are found in buildings more often than rats because they are smaller and are able to find more available entryways into a building. Mice can fit through a crack or hole one-fourth of an inch or larger - or about the width of a pencil.

Try to trap them before they enter the car. They are very attracted to peanut butter. I bought a box of 12 reusable traps from Amazon for less than $25. Using the peanut butter I caught 10 in the attic of our garage in 1 week. They are at least temporarily gone, but they'll be back.

[Piper1]

I know storage unit is different than home but I used this for our garage doors at home. They chewed through the side rubber moldings so I have flat metal electrical outlet covers screwed in at the bottom edge on the wall to prevent that again. A year and a half after doing that there's knock on wood been no mice signs since.

https://www.movingupgaragedoors.com/...hoC0lkQAvD_BwE

[kk7ds]

Originally Posted by HTM101

We have mice get into our home periodically. From what I've read they can squeeze into a hole nearly as small as a pencil, so I doubt you can stop entry.

Yeah, I know this is the case, I just don't know why they're choosing the Z instead of the M (repeatedly) so I figured there might be something obvious. Perhaps it being so much closer to the ground is a factor.

Try to trap them before they enter the car. They are very attracted to peanut butter. I bought a box of 12 reusable traps from Amazon for less than $25. Using the peanut butter I caught 10 in the attic of our garage in 1 week. They are at least temporarily gone, but they'll be back.

I should have mentioned: after the first incident we put down glue traps around the vehicles and we occasionally catch a mouse in one. We don't bait them because I guess it seems like an invitation to come into our unit that we don't otherwise want. If it was my house, I'd be able to change them out frequently enough that baiting could significantly reduce the population, but I figure with a big storage area, there's really no end to the source of available mice and thus encouraging them to come near the car is not going to help.

We also don't have access to power inside the unit and can't make any modifications to it (such as the suggestion about the door seal).

[Huz-Z]

Get a cat. You will quickly have no mice.

I know that may be problematic for a storage unit but just throwing it out there.

[grannyknot]

This is almost certainly where they're getting in, drainage flap for the fresh air vent. Passenger side near the firewall, you can't see it from above but right behind it is the interior fresh air filter.

The air filter would be a 30 sec. obstacle for a mouse, after he's through that, the whole interior is his playground.
The only way to defeat him is pull the air filter every fall and block it up somehow, getting to that filter is no fun, they hid it away in the P/S footwell.

[pungo]

I use mint spray for my vehicles that don't get a lot of road use during the winter. YMMV

[Steeler]

^ +1.

I soak cotton balls in peppermint oil and spread them around the storage area, underhood and a few in the cabin and trunk.

Bonus is the cars minty fresh in the spring.

[kk7ds]

Originally Posted by grannyknot

This is almost certainly where they're getting in, drainage flap for the fresh air vent. Passenger side near the firewall, you can't see it from above but right behind it is the interior fresh air filter.

The air filter would be a 30 sec. obstacle for a mouse, after he's through that, the whole interior is his playground.
The only way to defeat him is pull the air filter every fall and block it up somehow, getting to that filter is no fun, they hid it away in the P/S footwell.

So, this is exactly the sort of thing I'm looking for. However, I don't think this is the spot. I see no evidence that they got into the vents. No smell, no droppings and the filter is completely untouched. No chewing, no droppings in the filter housing when I opened it. I was shocked it wasn't dirtier just from use than it was.

There is a hole in the body above the pedals that I was wondering about, but it doesn't seem to pass through the firewall. They were definitely on the kick panel above the pedals because that insulation was the source of material for their nest.

[kk7ds]

Originally Posted by Steeler

^ +1.

I soak cotton balls in peppermint oil and spread them around the storage area, underhood and a few in the cabin and trunk.

Bonus is the cars minty fresh in the spring.

Does the minty smell linger? I feel like I may be the only one on the planet, but I *hate* to have my stuff smell "like something" even if it's an otherwise pleasant smell. I've seen a lot about the peppermint oil, so if that's really true and not a myth, that seems doable, as long as it doesn't permanently en-mint-ify the car... I'm guessing setting them on wax paper or foil would help avoid any residue.

[pungo]

Originally Posted by kk7ds

Does the minty smell linger? I feel like I may be the only one on the planet, but I *hate* to have my stuff smell "like something" even if it's an otherwise pleasant smell. I've seen a lot about the peppermint oil, so if that's really true and not a myth, that seems doable, as long as it doesn't permanently en-mint-ify the car... I'm guessing setting them on wax paper or foil would help avoid any residue.

I spray in the engine bay and the vehicle undercarriage, never anything inside the cabin, that's be a hard "no" for me. I don't notice any mint smell inside the car and I have a sensitive nose. Much of the spray lands on a piece of cardboard under the vehicle, so maybe that helps keep the mice away too

[Steeler]

Originally Posted by kk7ds

Does the minty smell linger? I feel like I may be the only one on the planet, but I *hate* to have my stuff smell "like something" even if it's an otherwise pleasant smell. I've seen a lot about the peppermint oil, so if that's really true and not a myth, that seems doable, as long as it doesn't permanently en-mint-ify the car... I'm guessing setting them on wax paper or foil would help avoid any residue.

Good call to set the balls on something in the cabin.
Not like you soak the balls in the peppermint oil.

In my experience the odour does not linger.

[mlquillin]

I had the same issue and sprayed peppermint oil on the insulation under the hood. It doesn’t smell inside but definitely keeps the mice away. I’ve heard that fabric softener sheets are effective too. Good luck!

[MarinerZ4C]

In addition to the drain for the fresh air vent pointed out by Grannyknot, there is another entry point under the hood, center of the firewall. It's the "scuttle drain", which is supposed to be fitted with P/N 64116915666 (Drain grommet, condensation water). It's not really for 'condensation', but for any water that isn't drained from the false firewall area by the two side drains.

This valved grommet is a bottle-neck that can accumulate leaves and other debris, plug up, and cause corrosion. Many owners or their mechanics remove the grommet/drain tube to prevent that. If yours is no longer fitted, you'll likely not even notice the 1.5 inch / 37mm hole in the overhang of your false firewall. My car came with the grommet missing. You will notice it if you have to remove and replace the trim molding below and in front of the windshield. With no grommet in place, it's a direct doorway for a mouse. I have the part, but I have not yet replaced it.

[jwolf]

I agree that the drainage vent is the entry. Close that up well with tape.

[kk7ds]

Originally Posted by MarinerZ4C

In addition to the drain for the fresh air vent pointed out by Grannyknot, there is another entry point under the hood, center of the firewall. It's the "scuttle drain", which is supposed to be fitted with P/N 64116915666 (Drain grommet, condensation water). It's not really for 'condensation', but for any water that isn't drained from the false firewall area by the two side drains.

This valved grommet is a bottle-neck that can accumulate leaves and other debris, plug up, and cause corrosion. Many owners or their mechanics remove the grommet/drain tube to prevent that. If yours is no longer fitted, you'll likely not even notice the 1.5 inch / 37mm hole in the overhang of your false firewall. My car came with the grommet missing. You will notice it if you have to remove and replace the trim molding below and in front of the windshield. With no grommet in place, it's a direct doorway for a mouse. I have the part, but I have not yet replaced it.

Okay cool, I will go check tomorrow and see if I can find that. The nest was right under the radio, behind the controls for the top, which sounds like pretty close to where you're describing, but I'll do some digging.

Thanks, this is exactly the sort of thing I was looking for

[zoomnad]

I don't put my car in storage and drive it all year. When it gets bad weather-wise, I don't drive it of course. Here is what happens (picture) when it gets stored.

[Efthreeoh]

Left side TPMS sensor harness:

[Efthreeoh]

I didn't take pics of the right-side wheel speed sensor and ride-hight sensor harness...

The dash was lit up for months.

[kk7ds]

Originally Posted by MarinerZ4C

In addition to the drain for the fresh air vent pointed out by Grannyknot, there is another entry point under the hood, center of the firewall. It's the "scuttle drain", which is supposed to be fitted with P/N 64116915666 (Drain grommet, condensation water). It's not really for 'condensation', but for any water that isn't drained from the false firewall area by the two side drains.

This valved grommet is a bottle-neck that can accumulate leaves and other debris, plug up, and cause corrosion. Many owners or their mechanics remove the grommet/drain tube to prevent that. If yours is no longer fitted, you'll likely not even notice the 1.5 inch / 37mm hole in the overhang of your false firewall. My car came with the grommet missing. You will notice it if you have to remove and replace the trim molding below and in front of the windshield. With no grommet in place, it's a direct doorway for a mouse. I have the part, but I have not yet replaced it.

Okay, so I believe you're right about this. With all the center console stuff removed, I see the top of this where it enters the cabin (item 8 in the diagram). If I stick my finger in the hole while driving, I feel obviously hot engine air very actively through the hole, which changes with driving speed.

Looking under the car, I can't for the life of me see how/where this neck would have been easily removed by anyone as it seems like it must drop right on top of the transmission (which is probably the reason for the S-shaped offset). Am I not looking hard enough or is it way too difficult to actually access? I'd love to not only confirm that it's missing but also replace it. We don't drive this in the off-season so no chance of it getting plugged.

If I can't easily access it, I was thinking maybe just some stainless mesh cut almost to size and pushed down (like the strainer in a faucet) into the hole to prevent them from chewing through.