my suggestion is to buy way too much fabric. cuz you know at some point your gonna want to do your doors, visors, etc. etc. and unless your positive you can find the exact same material again, you might be sol.
i like that this material has a 1/4" foam backing, would make some comfy ass doors, consoles and whatnot.
i got 3.5 yards and did a ton in my reg cab. i'd say 4 yards used sparingly and you'll have enough to last a lifetime haha