Just had a 06 Sport Supercharged in for the last couple of days with the exact same problem.
Traced it to the front passengers (Australian car) sill wiring loom
There is a White with Red tracer wiring splice that failed , located in the LH door sill. (Australia Car)
Hope it helps someone as it was a fun one to find
Regards
Mal
British & Swedish Motors
Narrabeen
Sydney,Australia