Woke up and saw this, thought a critter was in there. Came back from a drive later and found the wind did it. I fold down the back seats so the floor mats don't fly around. I hope the carpet doesn't fly out on the interstate or something.

 

Haven't had that happen, doorless/topless/freedom panels. I've only had the rear passenger carpet on the floorboard bubble up a couple inches, even a solid straight 2-3 hours on the freeway at 70-75mph.

 

Well mother nature started the mod for you... Rip it out and bedline the floors!

 

mine does the same thing. and then the floor mats in back start flapping around like a manta ray too.
i'll be taking all of it out and bedlining it next spring and then velcro down the rear mats. good thing the carpet tucks back in easily until then.