Maybe this is geographical, but my first thought was “don’t do it!”. I’m currently in So. CA and the last thing I want to do is put a semi-permanent decal on my rig advertising there could be thousands of dollars worth of camera equipment inside. For me, a magnetic sign for the truck would be a better choice; taking it off when I want to be incognito.
Edit...
Well, I see I should have refreshed this page before making my comment!
I went and visited your site and see that you use “images” in your name instead of “photography.” Maybe people would be less likely to think of cameras, but I still wouldn’t make it a permanent decal.