It'll take a brave man to try that out !!!
Not sure, but i think the Q5 handbrake is hydraulic ??? You can feel the brake pedal move when you apply / release the parking brake so i guess it's not a cable system. Also, If you stand by the car while someone releases the brake, you can hear the brake release.
At least it should stop me getting charged for a "sticky brake cable", twice (both sides from Lexus), down the line some time
Cheers,
Mike