While I was browsing products on SLP's website, I came accross part # 80046...Rear-Jounce-Bumpers that are supposedly necessary for rims size 17".. Are these really that necessary? Has anyone had any problems with tires and rear wheel well?

 

I replaced my old ones(cracked/broken) with stock before changing to 17x9.5 ZR1s' ..... No probs here....???? But its at stock height..Not lowered...

 

I see guys who use 17x11's gringing them down so they don't rub when you jack up the car with the body. Check out the sticky up top.