Read passenger side door area squeaked. The problem is the latch for the fold down seats. You have to fold the seat down and you will see a black screw with a 1 cm diameter head. Loosen screw, push down hard on the plastic that it's hold (where down actually means to the left because you want the plastic to move in the downward direction as if the seat was folded up but since it's folded down that's actually left at the moment). Screw back in hard. If you want to be really thorough, take screw out entirely, put in a rubber washer, and do the exact same thing as described above.

2007 RS4, silver on grey, hardwired V1, quad Laser Interceptors.