Someone in another thread used the MB sealant, no idea as to how it compares to the 3M. The 3M stuff can be had at any decent auto body supply house.

One of the issues with using lube us the sealer won't stick to the surface leaving a future leak path. Things won't leak right away and by the time you have an in car leak, the flange will be rusty.

I put some 3M stuff in the glass groove in the gasket ( not too much as it will make the gasket stick out too much ) , a thin bead around the cars flange ( where the pinch welds are ) , install glass then use the caulking gun to run a bead under the rubber to car area for a final seal.