There is a massive amount of space in the front for two tall adults, but the two rear seats aren't quite as accommodating. There's some bargaining room on the passenger side if the front seat's occupant moves forward, but it’s a squeeze to fit two adults one behind the other on the driver's side. Even so, head and shoulder room for adults with the roof up in the back is good.
Boot space with the roof up and divider moved out of the way stands at 400 litres, but divider and roof down, that volume is considerably less. It's good that the divider moves automatically so you don't need to get out and do it yourself, but there's really only room for a couple of large (but soft) weekend bags if you want an open-air experience. Even a weekend away with three or four people is going to pose a problem for luggage space.