I got my vapor from S4a and it does not have any problem with GPS. I am using papago and tom tom both can signal lock easily. The only gripe is with the softwares, both have areas to improve. Possible solution for you guys:

1. Make sure you are getting the original vapor and not the china made ones
2. Apply a layer of insulation like what my seller did for me
3. Place your iphone as close to the windscreen as possible to get easier access for signal, buy those dock that can stick to the windscreen
4. Do not tint your car too heavily if you have not yet done any tinting. I did tint my car to about 50-60%, still I can get signal when I put my iphone near to the windscreen. If I leave it near my audio console area, then no signal.

Hope this helps.

Don't think so. Rayken is still actively selling now. But he seems to be selling original Iphone 4 vapor case at really cheap price. Even got 2 buyers so far, and good reviews from the buyers...

Haha...get the real deal Vapor. I am thinking of selling mine. Black and Red. Those interested in real vapor 4 can pm me. I think I might also be selling my Hard Graft Iphone wallet. Been changing lots of casing. Anyone got bring in latest Ion Factory cases?

Original vapor does not leave any scratch in my iphone, that I can tell you. Interested? Hover over to my sales thread.

http://forum.lowyat.net/index.php?showtopic=1802377