FWIW, I have the road rash issue on my Midnight Silver, AWD LR (purchased in October '18) and it is directly related to a SINGLE trip I took over the Cascade mountains in Oregon back in January. I washed the car before the trip and there was no road rash and washed it on my return and it was significant, especially along the rockers and rear wheel well flares but also on the doors themselves. To address some of the speculation on potential causes here, I didn't have the aero covers on the wheels since I knew I might need to install chains. I wasn't driving aggressively since the road conditions didn't allow it (packed snow and icy surfaces). The roads were sanded over the passes, and in Oregon "sand" means pumice. After determining that the pitting was serious and couldn't be fixed with rubbing compound, ScratchOut or other DIY solutions, I brought the car into Tesla and they agreed to repaint the damaged areas under warranty. Judging by the comments in this thread, it sounds like my experience with Tesla is unique. Also, FWIW, I've driven my Audi A3 over the same roads in the same conditions multiple times and never suffered any damage whatsoever.