So this only happens to me in the last year after I was my car.
Routine is I wash , dry and back it into my garage. The next day or more when I get it to drive it forward out of the garage, in first gear the rear axle makes a pop before it engages and moves forward.
This has been repeated many times, I've tried backing in then engaging 1st and rolling forward and back and forth a few times ( just a foot or so) and it still happens. This does not happen when I back the car into the garage or any other space unwashed.
I'm I missing something here ? Could it be the brakes grabbing on wet to dry rotors ?

 

I would guess slight rusting between the brake pads and rotor releasing when pulling away. my S2k does the same thing.

 

i've had similiar experiance with 997

 

a slight film of rust develops on the rotors after a wash. Sound is the pads breaking away from the rust contact spot on the rotor. Normal.

 

I always take my car for a quick drive (5-10 minutes) or so after washing it to dry off the rotors.

 

either go for a short drive after-washing, or turn the car off, and put in 2nd gear and do not use handbrake, just remember your car is in gear I do that all the time, when i park my car outside and its raining for example.

 

100% normal , if you don't ride after wash it can do that! (rust on rotor)

 

I agree with the rest... drive that thing after washing. It is also good to get water out of door jams and sills... places you cannot get to by hand drying.

 

LOL I knew that this community would step in and answer my dumb questions. I usually use an electric leaf blower to dry it so there was not a need to drive and dry.
Its a weird feeling to feel a firm snap every time after the wash. Never had it with my C2.

 

Perefctly normal. But mine does it even when following the quoted procedure.

 

"They all do that"...