After 13k miles (with a service at 12.5k miles not mentioning any rim issues) when I was in to put new tires on (as it turns out while Sears sells the 21" Continentals dirt cheap, they were afraid to touch the Tesla for liability reasons) Tesla said that both rear rims were bent and needed replacing. I don't live in the prolific pothole country that is found in parts of the NE, and don't recall having hit any of the epic tire-eating potholes I've seen when visiting the NE.
Not having noticed any issues with handling or road noise, figured I may as well keep the old rims to see if the local rim repair place either saw any issue with them or would make them round(er) for less than the replacement cost of about 1k per rim. From pulling one of the rims out of the box, I couldn't see any reason whatsoever that required them being replaced.
Some would think that after springing for 100k+ for a car that I should nary bat an eye at paying umpteen thousand per year in new tires and rims. I'm a bit miffed that I didn't pull the trigger on the rim/tire insurance before it was yanked (wife was saying don't get it, I was partially convinced to get it), and a bit miffed that Tesla is in the business of sell to replace, not to repair.