NICE JOB DID YOU USE GENUINE AUDI SENSORS? OR WHAT DID YOU USE DO YOU HAVE PICS OF THE INSTALL
I used ordinary parking sensors, I think any sensors will work just take of the plastic around the sensors so only the sensor is left.
"http://www.biltema.se/products/product.asp?iItemId=93267"
Cost me like 30euro. Here are some installations pictures it is not a DIY but just some pic. of the job. it was very easy just drill a hole than put in the sensors. I used sikaflex to glue the sensors behind the bumper (a lot of sikaflex). Then I connect the power to the sensors whit the reverse bulb so the sensors will only work when I put in the reverse gear.