I purchased a 2004 Audi A4 Cabriolet with 16k on the clock in March 2008 and have spent quite a lot of money on the car since then replacing wear and tear items such as pads discs bearings etc. since then. I decided to have a gold service (http://www.audicare.co.uk/files/service_gold.php) done by Audi last week to give me piece of mind and maintain my car properly before purchasing some warranty (which I did from tesco last week after shopping around). The car has driven fine since the service, however on thursday when I tried to start the car (a week after service), there were a few problems......car wouldn't start first time which was strange. I thought it might have been down to a flat battery as I had hardly driven the car since it was serviced (less than 100 miles since I drove it home from Stafford Audi who serviced it), pop the bonnet in order to check the battery and noticed that my coolant level was very low which I thought was very odd given it had just been serviced and was full of coolant prior to service. I topped up the coolant and started the car up again and immediately noticed a white cloud of smoke coming out of the exhausts....basically the smell of burning coolant which I found alarming given that I'd just serviced the car. Got really paranoid and decided to call the RAC. It took the RAC guy that turned up less than 5 minutes to diagnose head gasket failure. The first thing he said to me was "have you got 3 grand" Since then I have informed Audi who asked me to do a compression test. I have had an Independent specialist look at the car and they are putting it down to an airlock in the system which most probably happened when antifreeze was changed! The problem I have now is I am not sure what I can do because. I am worried that Audi will deny that it was their fault and Warranty company will refuse to pay out given that I only purchased the warranty recently. Any advice would be highly appreciated as I am seriously depressed about this situation.