the hatch, or the car? i think someone measured the hatch, but try finding that kind of info around here. searching 'prime cargo space' turns up a post by tideland saying the gen 4 with spare tyre is 1 cubic foot bigger than gen 3, or 2 cubic feet bigger with no spare. i need height for recycling bins and the like. have to wait to see it in person i guess.
The car more likely. I would assume they wouldn't put it all in the tail end of the car or the front. More likely to be 50/50. iPhone ?
That extra length is compared to the 1GPiP (i.e. the Gen 3). The Gen 4 is a bit longer than the Gen 3 and the Prime is a bit longer than the Gen 4 (about 1" longer in the front and 2.6" longer in the back according to Nathan in the Walkaround video). At half a foot longer, it's almost the length of the Prius v.