Sorry to be a party pooper. I would be very careful about manufacturing logos and/or model designations.
Porsche AG is extremely attentive to anyone producing anything that has the Porsche brand or relevant model designations for commercial purposes. Look at how one of the forums just got shot down due to the domain name representing the GT4. A very high quality floor mat manufacturer also does not put "PORSCHE" parallel to the door sills, and could only put the brand name parallel to the seat edge. Then a very well known decal manufacturer (starting with "K" ending in "Studios") has also shied away and agreed with PAG not to manufacture model designation in the similar arrangement as OEM stuff.
I think the raised lettering is really cool. A great idea for proper model cars (Base, S, GTS etc for whatever model).
I think it is sacrilege to label the car something that it is not. It isn't your problem but a HUGE poser move for whoever labels their car, in this example, a GT. I would never advertise my car as a "Spyder GT" because it ain't. It is like buying a bottle of 10 year old Laphroaig (scotch for ye non-imbibers) and putting a 25 year old Laphroaig label on it. Not only is it fundamentally wrong to do, but your knowledgable guests that try it will shake their heads, say WTF, and throw you out of the scotch club.
In my opinion, stick with proper models (e.g. cayman GTS) and let the poser endure the shame as they cut the 'S' off.