I purchased my car on 1/31/14 and did a fair amount of research (the Tesla forums especially, as mentioned, go figure) and had a full paint correction and Opticoat Pro app done by Kris @ NE Detailing in Manchester, NH in March. I think I paid $1200 for the whole deal, including wheels & windows; I know that the paint correction, which takes a whole day under bright lights with a good hand, cost $500 (thank you FMC).
In any event, having been through 2 Maine winters, I'm really pleased with the results. As Kris said, just use a touchless wash in the winter and even if it's a little dirty it will look clean. That is true. Water still beads up on the paint.
I use Opticoat "no rinse wash" and "instant detailer" in the warmer months (hoping for one more warm day before next spring for the detailer) and it looks better than new. I'm in the car for the long haul so the cost makes sense. And, although not a film cover, I haven't had many gravel/pebble/sand dings despite our failing roads and the softer paint & clear coat.
So, for me, the OpticoatPro has worked well. I'd guess that other polymer coatings work as well, and there are plenty of user reviews on the web.