Aluminum is an electrical conductor, so as long as it's grounded to the rest of the chassis, you can use it. For the quick disconnecting part, all you need is one of these:

http://www.bellscb.com/products/antennas/Firestik/new/Firestik_K-1A.htm

I bought mine at Fry's in Sunnyvale. It was about 20 bucks. Since I rarely use my CB, I just keep the antenna strapped to one of my roof rack rails, and when I need it I just unstrap it and press it onto the quick disconnect, and I'm ready to go.