Boxster:
Since you asked our opinion, here goes:
What continent do you live on? Honestly, it makes a difference.
It sounds like you have already decided to color-change your car from silver, to orange/black. It sounds as if you have already asked the E9 group whether a vinyl top would be "acceptable", and received replies from Britain saying it would be OK. Am I on the right track?
- If you live in the UK, or perhaps in Europe, vinyl seems to be permissable. I guess coupes were delivered that way there, or perhaps it was a period conversion. So vinyl has some historic precedent there.
- Here in the States, vinyl tops are kind of a joke (contact me off-line, and I'll explain the socio-economic implications here). You might as well grow big sideburns, wear polyester bell bottoms, and install an 8-track player, as put a vinyl top on your coupe here. Paint the car Inka, Colorado, or MaryKay Pink - it won't much matter to US-based critics if it has a vinyl top.
Personally I think that silver is about the best color for Coupes. I also think that successive owners have a responsibility to maintain a car in the color the factory delivered. But hey, it's your car, and this is just one man's opinion.