We have the 20" Cont's on our Model X. Today I found a huge construction nail head stuck in the middle of our drivers side tire. I took it into Goodyear (as they were the only ones open today) and had them assess as to whether it could be patched. Glad it was as it wouldn't be too cheap to replace. The tire came off and I was optimistic. I heard one of the guys working on my tire state that "he's never seen anything like this in the 4yrs he worked there." I asked to come over and saw what he was talking about. I've seen a few threads on this on TMC since discovering this. But clearly this isn't something your delivery specialist tells you. For those who haven't seen it, it appears we have an inner-lining of foam in all of our wheels. It is glued in petty hard, but this is the first I've seen of this as well. Supposedly it helps dampen road noise by 8 dB. The guy had to cut a small patch of this away to get to the hole in the tire. But just fair warning for those of you who run into this. If you drop by somewhere to get your wheels replaced, be sure to be aware of the foam insert. From my reading it appears that you can ask Tesla to replace it if needed? I don't know what it would be like to "not" have it, but something to be aware of.