I lowered my mazda 3 an inch and a half in the back and put 17 inch rims on. I also have an 1100 watt amp and a box w/ 2x12 inch speakers in my trunk. With all that weight plus my car lowered, my rear tires are rubbing against the lip of my fender almost every bump i hit. People told me i have several options but i wanted to hear from you guys first what i should do. what is the easiest and cheapest way i can get rid of this problem?