how do i know if i'm rubbing?
 

im on 45 17 inch rims and i'm hearing this crunching noise sometimes in the rear after a hard corner or drainage dip angle slow drive over. I don't know if it's my rear lip or what. My fender has a lot of dust and stuff but that might just be the road? my rear lip has some minor scrapes here and there but i don't know if that is has anything to do with the noises.