Do I need Fender Flare Trim

I'm about to roll on bedliner my fender flares and the rubber gasket material that goes beween the flare and the truck is coming off. Could I just bedliner the flare and just install it? Is it there to keep the flare from rattling? I figure with bedliner material on the truck and the flare it should keep it from rattling.

 

Those gaskets are only there to give it a finished look. They are held on with two-way tape to both the flare and body. The flare might pull away at the top slightly, but of you don't care about a 1/8" gap I'd say leave it. They are roughly $25 a piece from the Toy maker.

 

Sweeeeeet, gunna order my bedliner material then. Thanks!!