[Azeka1]

At the $500 price point, your choices for a quality adjustable seat are a bit limited.

If you absolutely want to go aftermarket, then my suggestion would be to troll CL, eBay and various forums for a nice set of Sparco R100 or R333 seats (see pricing below).

You can also go with other OEM seats like those from either an:
- E46 M3: https://z4-forum.com/forum/viewtopic...ilit=E46+seats
- Honda S2K: https://z4-forum.com/forum/viewtopic.php?t=72750

- R100 $330 each New: https://www.sparcousa.com/r100
- R100 ~$500 set Used: https://cnj.craigslist.org/pts/d/spa...655452608.html
- R333 $525 each New: https://www.sparcoracing.com/r333
- OEM E46 M3 ~$250-$700 set Used: https://www.panjo.com/buy/e46-m3-hea...l-seats-367411
- OEM Honda S2K ~$400-700 set Used: https://longisland.craigslist.org/pt...663928580.html