This is an aerial off an Audi A7. The car is a bit of a special one, manufactured in 2010 it has 2 front radar sensors and a laser sensor for long range detection which is very rare for a car of its age and would with no doubt been a top of the range model when it was bought in 2010.
The vehicle came to us with a ADAS system fault, it was all down to this aerial antenna. The vehicle had various aerial antenna fitted to it controlling different things. The roof antenna (as pictured) was for GPS & navigation.
After various diagnostic tests we narrowed it down to the GPS aerial not working and then intern to the component itself which was faulty. What wasn’t apparent at first is why the ADAS system faulted because of this component failing? Although GPS is thought to be the future of automotive driving and vehicle to vehicle communication, we knew that the ADAS features on the vehicle did not rely on any information or data from the GPS as it was only being used for the satellite navigation system.
After looking through some technical data on ODIS it became apparent. The GPS was indirectly linked to various control units one of those being the front radar. As mentioned before the GPS was not giving the ADAS systems any information/data, it just happens that the vehicle software had been programmed to fault a group of control units when a fault occurred with the GPS.

Break down of GPS aerial