I've had my 2017 A3 Cabrio 1.4 TFSi serviced from new by my local Audi dealership.
Last year, they suggested I needed a brake fluid change, new plugs, and a new cam belt. The total quote was a bit alarming, so I declined the cam belt change. I probably should have declined the plugs and brake fluid!
Anyway, having researched the cam belt issue, I decided to go for it this year. The car has done 16,700 miles, mostly in long journeys around Europe, and it sits around doing nothing for most of the year. The tyres dried out and cracked because of this inactivity, so I fitted a new set last summer.
Audi charged me £599 for the cam belt work, on top of the standard cost for the annual service. I was disappointed to find that they hadn't replaced the water pump, but they were adamant it wasn't necessary, because the pump was in A1 condition.
So the bill for the cam belt change was £599 without a change of water pump, but with a free MOT thrown in.
Just for information - I'm not recommending anything!
Steve