[Quacker]

Originally Posted by taylora

Not sure that's correct.

Autohold maintains the foot brake pressure when you come to a stop, releasing the held brake pressure when you press the accelerator - using servo pumps and vacuum valves. It does not engage the electric parking brake unless the car has been stationary for a while - seven mins?

The parking brake is indeed electric but it's separate from autohold and only work on the rear wheels. Autohold uses the brake servo pressure and works on all four. Two separate systems for safety.

Read my post again. It is clear and correct in the most part but you may be correct in that it uses the same system as hill hold assist, but without the 2 second timer release. Neither the hanbrake nor the other system make any significant noise on mine apart from the pads releasing.