You're right, he didn't specify if the "candidate" was from a 2 or 4 door, I would hope that the one he picks has the tipping back just for the reason that you noted and the simple rule of thumb is 2 door cars had the tipper and 4 doors are rigid. I had to re-read your comment... I thought you were noting a friend's issue. My bust.

papawfalcon: there is usually 3 to 4 inches between the door panel and seat. The biggest issue you are going to have is seat foundations/track mounts -- having enough support for the seat through something besides a single layer of sheet metal.