A week ago I noticed that my brake was intermittently failing and the ABS light came on and off on my A3 sport. So I took it to Audi and they reckon it was the ignition switch so I got that change. I picked the car up yesterday and last night the same problem occur with the brake lights not working intermittently. I did noticed that when the car is cold (started up when not driving it for a few hours) the brake lights works. However when the car becomes warm (operating at its normal temperature the brake lights do not work. Has anyone have any ideas of what the problem could be? I spent alot of money getting the car fixed and I am worried that Audi will charge me more for a problem they did not fix in the first place.