Found this aging post, closest oneI could find to get an answer to my dilemma:
I have '05 roadster base (vinyl seats, manual, not heated, all black). 90K miles took a toll on the stuffing and seats need some help. (Vinyl itself holding up pretty well)
Wondering if leather cushions from higher end model will fit my manual seat rails (I would not use the heater connector - or I could make adding that another project).
There are both seat cushions and entire seats for sale on eBay; 2-tone leather seats would be a nice winter project / upgrade.
Thanks for any thoughts.
D