I just returned from a trip to Spokane WA…Car top signs were all over the place… Spokane is the home of http://www.autosox.com and it looks like their marketing efforts have worked well… But I also saw quite a few fully wrapped cars including one for Dominos that had some reflective material so their logo and phone number reflected back when your headlights were pointed at the rear of the vevicle…There is no doubt in my mind that getting in the face of your potential clients works…
The best car topper is the one that sits on the top of your drivers car. If it’s legal to light them definetly do that. It makes a big difference. You extend your viewable sign hours when it’s lit.