Very interesting, how do you control the steering wheel? Most solutions I've seen for that were either really clunky (and unsafe, as they obstructed the airbag etc.) or used/replaced the power steering. I just assumed you would have used the existing interfaces, I know for a fact that at least the current A6 has all the necessary hardware on board, and am pretty certain that the A4 has the same for park assist.

Have you thought about selling your system directly to manufacturers for integration? I'm certain that there are chances if you're able to deliver a working component that can simply be integrated into existing models. Most of the current assistance systems aren't developed in-house but come from one of the big third party suppliers.