mine does double sound on locking, did not hear that when autolock was not active.. this is due to the fact that autolock is SINGLE lock action, and the keyfob is DOUBLE lock function... I just did not realize, that it was LITERALLY double lock...

single lock does not lock the fuel door and allows the handle to unlock the door from inside on first pull and open the door on the second pull, the double locking does NOT allow the handle inside to unlock the car... and the fuel door is locked - so, I gues, the locking module (EWS or DWR?) needs to get out of one mode before entering into the other...

when the car is locked from the lock button inside the car, supposedly in case of an accident, the locks do NOT unlock... when the car locks with autolock feature, than the lock autoUNlock in case of the accident...