Just a little FYI on the Advance and Fold-A-Cover they are pretty much the same thing. The two companies are owned by brothers or cousins one and they are in the same town, Caledonia MI about 4.5 miles apart. They do have different mounting and latching mechanisms. The siderails on the Fold-a-Cover are mounted to the truck bedrails into the standard holes, on the Advance they are built into the panels of the cover and fold up with the cover. On the Advance their is a heavy rubber strip about an inch wide that you put on the bedrails with 3M tape and a bulb seal inside of that mounted the same way that the cover sets on when closed. The latch mechanism's on the Fold LS and the Advance work very much the same. They both are a spring action slam latch, where the Fold LS uses the key to work the latch mechanism the Advance has a lever that sticks out through the front and rear seals. Here are a few pics of an old Advance display that I leave outside here at the store, things been used as a workbench, table, catchall, it has taken a good beating over the years. Advance also has a new cover called the G3 Supra which has a full length rail that mounts like a Roll-n-Lock rail that the cover sets on and lathces to.

I see you haven't gotten one of the G4 displays yet either Gasm. Called them this morning and they charge for them now.

 

Sorry fro the very late response...

Fold-a-cover told me they were aluminum foam core panels.

 

I had a fold a cover and what a POS! I had a hail storm come by my truck was fine fine but the fold a cover looked like tiger when his wife found out..... Also the keeys kept breaking because they where so flimsy.