Has anyone experienced this with your A4? Or any Audi?
On my 2008 A4 2.0T Multitronic (barely 400 miles), when I stop for a red light or sign at an elevated slope intersecton (facing upward about 20-25 degree angle) my brake pedal start to feel 'hard' and it felt like the power brakes has been lost momentarily because I can just feel my foot 'sunk in' and it felt stiff while applying the pedal. There's also a very low audible long 'beep' coming under the cabin somewhere, perhaps from under the dash area? It sounded like the computer or some control unit. When I reapply the brakes, it powers and again becomes hard and stiff, and it would intermit along with the very low audible long beep when I pump it. What the hell is it? This happens mostly on hilly areas facing up when the brakes are applied.
I remembered when I pulled into a parking stall once and heard the same low faint beep, right after that, I shut the car off and go about my regular way because the car was so new and I thought it was nothing (it probably is nothing).
Has anyone felt/heard the sound before?

 

I dont' own anything so new so I'm not really sure, but could that be a hill-start assist system. Some new cars are designed to hold the car in place when on an incline, preventing you from rolling backwards.

 

1st thought is did they put in a hill assist feature? second would be something w/the security, where the angle means tow?