Okay, my son managed to pull the sub-seal loose from the top of the passenger door on my 2010 RL. I'm looking at this and I can't figure out for the life of me how this thing attaches to the door. How do I re-attach this thing so that it will stay?

 

Yeah, having exact same issue. Kids, I tell ya....

 

it's a gasket. push it back into the grooves.

 

^That new avatar is throwing me in a loop crabman, but I agree.