I don't think saying "120v isn't enough, you need to rewire your entire house" is really accurate either. Most water heaters, stoves, and some central heaters run off a merged breaker for 240v. You can easily use one of those lines for the car if you don't plan on taxing the thing the entire time (though I figure if you have 50k for a car you have 1k to add an extra circuit and wire your garage up for it).
Yes, although at least in my view part of the selling point is that we have plugs everywhere, so you have electricity anywhere right? Well, hunting around for a 240V plug is a big harder than 120V.
Also, even though 99% (???) of the world is on 240V, I think the current rating on those circuits still limits power to around 2kW sustained.