It seems possible. Not Audi though - probably better tbh:

https://www.hazzydayz.com/genuine-front--rear-or-front-or-rear-only-optical-park-sensors-7957-p.asp

 

HazzyDaz have fitted a rear view camera for me today and I cannot recommend them enough they will be the ones to do this job for you.
There not cheap but we all know you get what you pay for and I got a two year warranty, they actually do work for some Audi dealers

 

Strange Audi claim they can't do it for you. I bought a pre-made example which had everything I needed aside from front parking sensors. The dealership agreed to install them for me before I collected the car.

 

Hi tigor - found my way to this thread, even though it's a bit old, after having a question about front sensors. Just out of interest, did having the front sensors installed enable the optical mmi option for the front and rear parking sensors?