Chris,
my opinion is this. even though you say its "just the kids driver", you should still put the quality interior in it. it still should fit correctly no matter what. im sure its going to be a nice car on the outside, why not make the inside just as nice.
i would drop the 900 bones and get the whole shootin match, heck, i paid $900 for just door panels that dont fit !!
and mine is a racecar ! i was going to have them(SMS) send me the seat material for my bench that i want to put in the car, but probably not, we'll see how they "fix" my door panels first !!!