It might be worth your trouble to contact the Audi Pre-owned managers at any dealerships within your geographical area and let them know exactly what you are looking for. The perfect car may come in as a trade, and if they have your name and number, they'll let you know.

I (personally) would follow up a time or two to remind the same person they have a potential new owner--make sure you aren't forgotten.

 

I got my 2001 A4 1.8TQ tiptronic for CDN $19900 with 99,000 km. I spent $2500 so far for maintenance stuff, but no regrets.