The idea I have in mind for the colors is to get the feeling of a 1940's or 1950's gas station or a garage. Vintage paper, cardboard, greasy hands, oil drops, heavy metal tools, gas station insignia... which colour could take the visitor back in time?

1-3 main colors and few effect colors for spicing up.

Red, aqua, and black.
When I think of the 50's, those are the colors I think of!

These are the kind of colours I think of:

I came up something like this but... i don't feel this would be the one.. Roadside Gas Station

Hows something like this:

i know its an old post but here are some pictures i took of a vintage car show in California, maybe it will help if you still need it http://public.fotki.com/russkayadusha/trips/pasadena-car-show/

Use something related to red