Audi A6 or BMW 525i?

I am looking into buying either a 2001 Audi A6 2.7T Quattro or a 2002 BMW 525i. Both cars are around the same price, mileage, etc. What are some of the outstanding features of each other car? Reliability/Quality/Comfort/Safety and so on.

Audi A6 or BMW 525i?virus protection

audi, don't depreciate as much as BMW's

Audi A6 or BMW 525i?agv

I'd go for the Audi. I have a pic that shows reliability ratings but I can't use IMG codes :(
I would go with BMW because I worked on both cars and found BMW be more reliable. However, BMWs are generally abused cars. That ZF transmission used in BMW doesn't last long when the car is pushed. Many will fail around 120 - 150K if not serviced regularly. Also BMW use life transmission fluid. When they said "Life" long, they meant 100K miles. If you pull the transmission spec, and look up transmission fluid used, it is actually 70K long life fluid (made by Shell or Exxon depends on the model of the transmission) so you want to flush the transmission even if the BMW dealer would not recommend that you do. If you want to get one, get one with manual transmission.
on this one you have to be careful about the turbos on the Audi normally the A6 is as reliable if not more reliable than the % series (the newer the car the more true that is pre 2000 BMW definitly had the advantage for reliability) unless you are going to tune the car i would go with a NA engine not a turbo the turbos are nice but expensive to replace and the need to be replaced every 70K. i think the 525 feels sluggish i would look for an Audi 3.0 A6. the Audi is more comfortable than the BMW but that is really a subjective, could be different for everyone. the BMW has slightly better handling characteristics and slightly better feed back form the road but the Audi is no Lexus here its pretty good as well. if you live in the north the Quattro is AWSOME in the snow the rear drive BMW is definitly capable of being driven in the snow for a confident and somewhat skilled driver but don't let just anyone take it out in the snow.