I know the law as posted here sure seems to say you can't have these things stuck to the window, but I think the law they're referring to is the law that you can't have things blocking vision - fuzzy dice and the like. This is in a way the same (blocks vision) but at least it does something for driving. My mom has one in her car in San Diego - I don't think she's worried. I'd just put it on the window - it's probably nothing more than a fix-it ticket if you get pulled over and it should be easy to remedy, you know?

 

I have a 2720 sitting right above the vents with the wire going in the top vent. Looks very nice.