As mentioned above, I think you have to follow an individual style that you are happy with, rather than trying to conform with "rules and regulations" of a particular "theme".
Here is my "german looker" (term used fairly loosely) - 17in wheels and 4 wheel discs along with type IV, autometer gauges, roll cage.....but stock seats, carpet, chrome trim, audio system etc....so I just did what I liked and it turned out alright (in my opinion!).
