My Roadster's within a few hundred miles of going out of warranty, so I took it in for its 36K maintainence.
Since the warranty was almost done, my local Ranger decided to go above and beyond and look for any possible problems with the car. In addition to more normal things, he found a tiny crack in a weld in the subframe:
He told me that if the crack got bigger and the weld broke that the car would start making a clicking noise. While he could have done nothing or just redone the weld, Tesla's policy is to replace stuff if it's at all wrong. So, he decided to replace the entire subframe assembly. This requires removing the entire back half of the car. He sent me some pictures of it. In case you ever wondered what half a Roadster looks like (without the benefit of a horrible crash), wonder no more:
And remember, this happened just before the warranty expired, so Tesla covered the entire expense, while they could have waited for me to notice the problem and then charged me for it.
You've really got to apprecieate Tesla (and the Seattle service guys), it's hard to imagine getting this kind of service from any other car company.