I've said as much in other threads. Given mediocre sales and the high existing competition for the futuristic vision for their unreleased future products, I think the correct price for TSLA is USD 10-20/share, and no that's not missing a digit.
For Mars… well, I like the idea of settling other worlds and expanding and yada yada yada, but Musk has repeatedly demonstrated he's not got the personality to actually do that right and not lock people out of the base for disagreeing with him. Plus, if you Muntz* a life support system or a food supply or the walls on a Mars base, everyone can die before replacements arrive.
This madman's extraterrestrial dream™[0] will do more harm than not.
[0] Nightmare - ¡yay let's destroy Earth to build a dependant-upon-Earth colony! /s
Also: if you want to drive a vehicle that actually saves the planet, buy a hybrid (plug-in, or not).