1. UPR A/C delete pulley instead of an FRPP A/C delete bracket. Looks dumb, made a weird whistling noise from the holes in the pulley, and the bearing in the pulley went bad after less than 9 months. The A/C was already gone from the car when I got it (idiot just tried to run a short belt with the stock A/C bracket setup, belt was rubbing itself to death on the water pump pulley), and it's just my weekend car so I don't miss having it on there, but the UPR pulley was a VERY poor choice to make the A/C delete "right";
2. UPR cat'ed X-pipe. Should have gone with a brand of X-pipe with a transmission crossmember hanger. Stupid thing kept sagging at the flange where it connects to the flow tubes, so I was constantly jacking it up and having to re-tighten it. That, and I had to notch the tranny crossmember to even get it to bolt up because the damned cats are welded about one or two inches too far back. AND the whole thing is an inch or two too long, so it makes my tailpipes stick WAY out past the rear bumper. I just keep it in the spare room to swap on/off for smog testing purposes and run a Jeg's off-road X-pipe the rest of the year, but I would have preferred to have something on there that I don't have to constantly keep swapping out every year;
3. Saleen airdam. Just didn't look quite right on teh Notch (better suited to a hatch), I was always paranoid about hitting parking bumpstops with it, and I hated having it attached with screws (looked Über-ghetto) but I don't think double-sided tape would have held it on worth a crap, either - didn't want that thing peeling off and shooting underneath the car while I'm on the highway or something.
At least I was able to fill and touch up the paint on the the holes I drilled in the stock LX bumper.
4. Side-exit exhaust with Dynomax #17676's, swept-back outlets, and an off-road X-pipe. I had a very similar setup on a prior '89 notch and it looked good and sounded good, but I'd made the outlets straight-exits with flattened oval tips that didn't stand out so much, and it had an off-road H-pipe ahead of it. With the X-pipe, for some reason it sounded like a dump truck, but with the H-pipe the prior setup had sounded like an old Mopar. Wound up going back to my
Pypes Violators and Dynomax stainless 2.5" tails.