I only replace stuff that wears out!
My struts gave out. After two bad sets of struts on my car from Autozone, I thought maybe my springs were worn. So copped some H&R's for better price than OEM replacements.
My brake discs have never, ever been replaced. So i'm about to replace them with those fancy smancy brake disks and pads probably. Unless the cost is tooooo much more than OEM discs.
My muffler has a teeny weeny hole in it. So i'm going to replace it with an aftermarket muffler--only SLIGHTLY larger than stock.
Had to do the stereo though. Parkin' Lot Pimpin' is a must!