Rob you must be thinking of his Rage seats. they where universal seats with universal sub frames. aprently they where a ball ache to fit. but they did it in the end.
You wouldn't belive how many emails I've had from people seeing the lude seats in my car. I can never help them as it's the previous owner who fitted them, but from what I've heard if you unbolt the new seats runners then your old ones should fit right in their place. Then just bolt back into your car