We don't have any interior in the car so space wasn't an issue. We originally tried the fighters with the interior in it and they hit the door panel. We are currently running a fia certified momo seat. The other thing to consider is that the main reason for a racing seat is for the addition of a 5 or 6 point harness. The factory belts are not recommended for use with a racing seat. What you are wanting to do is a huge commitment. It would require at a minimum a harness bar to be installed, which is no small feat in this chassis.