There is no question that a fully assembled bicycle fits in a Prius. Attached is a photo with a road bike installed.
This shows the clearance with the door closed - nearly a foot. A previous PC member suggested that this was impossible, and that the front wheel needed removal.
I put 16 cases of fruit in mine, and had room for about 3 more! (I think I went considerably over the weight limit ,though!)
I've had quite a bit stuff into my Prius over the years. A 3-wheel recumbent bike is the largest object, with seating for 3 available still. Last weekend, it was 2 bikes inside. You do have to take the front wheel off for that... especially if you carry other cargo too.
