Did a search for this but nothing came up. I recently noticed that the hump on the middle of the floor in the back seat is unusually soft. If i step on it, it feels like my foot sinks into it an inch or two as if there's hardly any support... is it like this for anyone else?

 

if you mean the one right in front of the AC vents/console, it has some padding under it. I think its about 1.5 inches of some white padding.

 

Thats just how it is. My 05 tl had it, and so does my 07 type S

 

The lesson to be learned is ... never ask a third person to sit in the back seat and never place legs or other appendages on top of the hump. And yes, my 06 TL has the same thing.