..and just different materials? Looking to recover my 88 vert seats, they appear to be same shape as 86 -88 leather in non verts, is this right?

 

Vert seats were made with a 'vert-specific perforated leather.

 

There were also differences between the lower model seats, and the GXL/Turbo seats. These had adjustable headrest, and thicker side boulstering, as well as lumbar adjustments. There is also some difference in the backing of the seats, but I think that was just in the pad and not the seat itself. Vert seats had much larger head areas, with speakers built into the headrests.

 

There were three basic styles of seats.

The base seat. Non adjustable headrest, all one piece backrest. Found on the 86-87.5 Base, 86-87.5 Luxury coupe/GX, 86-87.5 Sport/GS, 88 SE, 89-90 GTU, 91 coupe w/o option package A

The Turbo seat. Non adjustable headrest, two piece backrest. Found on the Turbo, 87.5 Sport, 88 GTU, 89-90 GTUs.

The GXL style seat. Adjustable headrest, One peice back rest. Found on the 86-90 GXL, 91 coupe w/ A package, and 'verts.

Note that the 'verts also had an option for headrest speakers and leather in 88, but leather and headrest speakers were standard in 89-92.

Of course the GXL and Turbo seats also had the option of leather, (but no head rest speaker option).

The S5 versions of the seats had slighty different foam/shape, on the bolsters and seat, but unless you had the two series next to each other you might not be able to tell the difference.