I have a 2007 A6 3.2 Quattro with 79k miles. About 6-8 times over the past 9 months, I’ve had to put dry gas additive into the tank to get the car to start. Garage is a bit damp, but not too bad. Brought it into the mechanic who cleaned the fuel injectors but didn’t find anything. Doesn’t seem to matter if the tank is full or close to empty.

anyone had a similar issue?