If it is a track car, then they are worth looking into. A street car...not so much. I ran all poly suspension & driveline parts for 5-6 years on my daily driver, mostly because I was too broke to pay a shop to press in new stock ones. Yeah, going back to stock rubber was nice...handled just as well and was 10x quieter! Any poly suspension part for a 325iS will fit a 318iS. I don't recommend it on a street car, though.