It's safe. Trust me. Just make sure it's a soft bristle and if your really unsure, wet the brush. It's gonna be in the cracks, so even if it does scratch (never has yet) you cant see it. The trick is to gently slide the brush back and forth in the crack. It loosens it, or use a q-tip, removing some cotton to fit the space.MRQturbo said:i use a toothbrush on my rims...but never on the car itself......