Rear Vent coming loose

[Sand Cruiser]

I noticed this evening that the external rear vent on the driver's side of my LC is working its way loose (this is the one on the outside of the vehicle next to the brake lights). I tried looking on techinfo.toyota.com for info on how it is attached to the body but I could not find anything. Does anyone know how this part is connected to the body, and what would be the best way to fasten it on again.

 

[NMuzj100]

Picture ? how loose is it?

I might try and take it all the way off before it gets lost on the road. Once it's off I bet it would be pretty easy to see what's wrong.