I recently installed a great set of coil-over shock and springs in an effort to improve handling and my car's look. While the decrease in gap from the top of the tire to the bottom of the fender lip looked great, I found after inspection that my rear tires were very close to rubbing the fender lip in the back.
What to do? ROLL THAT FENDER !
Tire Rack sells a great tool that when used with an industrial heat gun (and patience), got me out of the jam I was in.
The fender lip rolling tool features an adjustable arm and a non marring roller that will slowly bend the fender lip up and out of the way for additional clearance. It is essential to use a heat gun to keep the paint flexible enough to avoid cracking as the metal is worked.
You can see detailed instructions on the tool in the User's Guide
If you've recently installed bigger wheels and tires, or lowered your car like I did then you may want to consider picking this tool up!