When I drove from Maryland to Wisconsin I bought a Passport 8500 at Best Buy in Maryland and returned it at Best Buy in Wisconsin. This was two years ago though, and since then Best Buy has instituted a mandatory 15% restocking fee on all radar detector returns.

The 8500 is supposedly the best thing out there aside from the V1 and it did alert me the one time on the trip that a cop was using a radar gun near me. I don't think I would actually get one though, just for that trip I couldnt stand having the thing hanging off the windshield and the cord right there in the middle of my interior. Not saying it doesn't do its job well, but eh. I've gotten one speeding ticket ever and I was 16 at the time.