I figured it would be easier to reply here than start a new thread about this.
I'd be interested to see if anyone has figured out through VCDS how to increase the speed at which the parking button can be pressed or enable all the sensors all the time?
I'm one of those who wishes Audi at least made it an option to enable all maybe through MMI. Was back home a couple of months ago and got a Citroën DS5 hire car, and the way their parking sensors were set up saved me from hitting a few concrete posts at Gatwick without even knowing the car had them. IMO if I wasn't familiar with the A3 and got that as a hire car, I wouldn't have known to hit P before the wall.
I get why P shuts off above a certain speed because the backup camera can be a distraction, but the sensors only working when I'm in reverse or press P below a certain speed seems a bit daft.