They're striking me as hard to find. I can get corbeau's made that way, but what else offers slide and recline adjustability with a harness slot in the lower cushion?
My Schroth harnesses say they can be mounted either way, however, in a Mustang (and I imagine most street cars) the left side belt mount is further back than the right side one. This puts the left side out of the area they recommend for anti-sub strap mounting.The ones designed for an upright, sedan-style seating position do. The ones that don't are for reclined, formula-car style seating position.