I just bought a used '04 Aviator with low miles and love it. I have some questions. How can you tell if you have AWD? I know it doesn't have the optional AdvancedTrac, and the VIN number says its AWD as the dealer sticker also said this, but I wondered how to tell for sure. There are no lights or anything inside that displays 4 wheel drive. Should there be a transfer case in the front?

I also seem to get different answers about the radio. I don't have the navigation, but I do have the DVD in the back. I would like to add satellite radio at some point, but I read that you can't do this if you have the DVD system also. If I can add this, what is the most cost efficient route? I would like to use the factory head unit.

The Aviator is AWD not 4WD that is why there is no way to switch it. It is a full-time system. We had a Mountaineer before our Navigator and it was the same way. If the VIN code says it is AWD then it is.

I wondered the same thing .Look for a diff in the front .That's the best way to find out.