[mpathic]

Catching up on ZPost threads.
For B Street, start with
Use the largest front swaybar you can find. I'm using the H&R 31. An unlimited budget would go with a hollow tube bar to save a few pounds. Need to use stock swaybar links, and expect they break sooner or later so carry spares.
Koni DA rear shocks, listed for the Ford Mustang. Saves $$$ vs E46 versions, has the unicorn top adjuster for rebound and an indexed click screw on the bottom of the body for rebound.
Koni SA 'cut a strut' style front struts listed for E36, installed in E36 //M3 strut tubes for the same installed spring height. Will need to cut 10mm off the bottom of the upper strut mount to fit the Koni threaded shaft through the E85/6M upper strut mount.
See: for pictorial of this strut adaptation.
Battery: Use a small light race battery.
Exhaust: remove the rear resonator and x-pipe. Also removes some weight. Replace with 2.5" x-pipe, round out the square pipe end sections using a pipe expander. Then you learn that the factory mufflers flow great, its that awful resonator and pinching x-pipe that's the real flow problem.
Any air filter can be used. I like the Pipercross over the K&N.
Spark plugs: single electrode NGK DCPR8EIX installed with the opening toward the intake valves.
Oils: Redline.
Empty the washer fluid bottle for less weight.
Extremists will use worn thin rotors and brake pads, and titanium lug bolts.
Wheels: Lightest you can find, with as little offset as the rules allow or use spacers. DForce and Apex don't make an 18x8 so you need to search old stuff. I found a set of old very light stock size SSR Integrals with 40mm front offset, and 26mm rear offset. Will use 5mm front spacer.
hth, good luck.