I'm not talking about bling things (19 inch rims, jdm dress up) but functional things people buy thinking they are improving performace.
One guy I know bought 150lb injectors, thats not a type-o 150LBS!
No matter how much tuning he tried with a laptop he could not get it right (how much can you detune an injector that large?)
He switched to I believe 40 lbs and now his car runs great.
By the way if anyone wants 150lb injectors for a chevy 350 I know where you can get some cheap