Seems exactly my case. My approved used audi q7 plat 65, bought in June 2020 , has brake servo fault and start/stop fault in July (roughly 4 weeks after purchase ). I was hold to wait for 4 weeks to get appointment for repairing, during the first 3 weeks, I drove roughly 300 miles, and then there is red indication saying “brake fault- park safely” instead of the previous two yellow fault. Today I send it to nearest audi dealership, and was told it will cost £3500 to replace brake servo sensor and ABS module as well.
The car is in a two years warranty as approved used audi, So hope it is just a show bill and will be fully covered by warranty. I will check it tomorrow morning.
