If I were you I would take your Audi to a specialist Car Alarm/Radio/Electrician shop for a second opinion. (Check on the net or yellow pages) I used one of these specialists for something else (not an alarm fault) and they found a second hand part-much cheaper. In any case, a good, qualified, vehicle electrician might do a better job checking if the problem is just a poor connection? Also, what is the age of your Audi? If it is over 5 years old fair enough but if it is any younger you might try VAG UK HQ for a 'goodwill' contribution? Good Luck!