I love my '06 GXP but I am running into 2 problems and wondering if anyone else has noticed these as well.

1) When I first start my car and back down my slanted driveway and apply the brakes I hear a sound in the rear breaks like anti lock is kicking in. This only happens when im 1st driving my car. Anyone else notice this?

2) When starting my car after it has been off for a while (a few hours or more) I hear a clicking noise in the engine. Problem is louder when its cold out (30deg F and below i really notice). The dealer shop says that is normal for new GM cars, but it does not sound normal at all. ANyone else experience this?

Also - does anyone know where i can get accessories for the GXP? i want to replace the headrests as I hate how far back they are...