This has got to be one of the most ridiculous ideas I've ever heard. I mean, c'mon, launching a Tesla to Mars as the first payload SpaceX delivers to the red planet? Apparently, they have no idea how much it costs to park a vehicle on Mars. You think parking a car in downtown Manhattan is expensive? Parking a vehicle on Mars is downright, well, astronomical.
A space in a secured, heated, attended parking garage, near any crater of significance, is gonna cost an arm and a leg. Plus, it's expected that the attendant be given a reasonable tip, considering the hassle involved dealing with the frigid temperatures and brutal wind storms that can come out of nowhere and make for an overall, very unpleasant day for anyone caught up by one. And if you don't, you can be sure your vehicle will be keyed the next time you park it there. Garages on Mars never cover incidental damage and try suing them in a court of local jurisdiction. In all of recorded Martian history, no human has ever won a civil suit against any Martian enterprise. There are no kangaroos on Mars, but their courts sure are.
Utterly ridiculous.