If we've got 6 players and everyone pitches in 1 point, that should be enough for a modest tower HQ and vehicle.  However, I don't think the "one point for every vehicle after the first" lets you use them all at once, the idea being that you don't have to pay for things you can't use at the same time.  The Batboat and Batcoptor just sit in the Batcave when Batman's driving the Batmobile, after all.  The easy way to do this is to buy a "team bus" instead.  Bump the Size of the bike up two levels so it can hold a number of people, and that way only the driver (or an NPC driver) need to worry about vehicle skills.  Also, put an autopilot on it so it doesn't crash when everyone jumps out to hit the bad guy.