@InfinityApprentice: The base can read three hex discs, so in principle I don't see why it can't take two vehicle hex discs (for the two local players) and the racing expansion/playset piece.
Interesting that they are going to allow existing vehicles from the toy store. I assume this is limited to ground vehicles and not flying or air/ground-convertible vehicles for speed reasons? Motorcycles? I haven't counted recently, but if they're going to let you keep 2.0 toybox unlocks that's a pretty fair range to choose from.