I am thinking of buying a Roadster. What should I look for? What are the pros/cons of various versions? I have a Model S and a HPWC - I believe you can use this with a Roadster assuming that you have an adapter and turn down the current (I think). Doesn't that require a particular firmware in the Roadster? What else should I look for? Hard top, soft top, etc. Isn't there supposed to be an upgrade coming out soon? Will all Roadsters be upgradable?