Braun9

My 2001 Audi TTQ Coupe 225hp I bought new now has 174,000 miles on it. Lately, I noticed the rear tires had worn very unevenly, cupping in a diagonal pattern evenly across the tread. I've had several people tell me that the rear suspension needs to be replaced. However, pushing down on the rear of the car does not produce any noticeable bounce to indicate they are bad. Also, the car seems to drive fine. I'm not looking to put a lot of money into this car, but I do enjoy driving it, so I would like to keep it for a while. I currently drive it maybe once a week...

I've been quoted $800 or so to replace the rear shocks (plus an alignment), but I don't really want to spend that much. I also saw a pair of Bilstein Touring Class shocks for much cheaper on ebay (part number 19145570). How difficult is it to replace the rear shocks yourself? Are there any good DIY guides online? What about special tools? I am pretty mechanical, but just inexperienced when it comes to suspension...

Also, if the rears are bad, how can I tell if the fronts are bad? Is is normal to just replace the rear shocks and not do the fronts, or should I do all 4 at the same time?

Any advice you can give me would be greatly appreciated... I love my TT and would like to be able to keep it for another 20 years or so.