ABS/esp light would come on after driving for 60 minutes or more, usually went off if vehicle restarted, this became more frequent over course of 10 months until light stayed on all the time, wheel sensors had to be changed at significant cost to fix problem.

- Shelburne, VT, USA

Audi 2001 A6 2.7T tiptronic while in D transmission mode, car does not accelerate per accelerator input after using the brakes. There is a delay of about a couple of seconds before car accelerates. This happens after braking from low speeds followed by gentle acceleration and also when braking from higher speeds followed by either gentle or aggressive acceleration. Often there will be a pronounced jerk when the car starts to accelerate after the delay. Safety issue typical situation: When crossing medians to merge with traffic in the opposite direction, oncoming traffic have to brake heavily to avoid a collision because the car is unable to accelerate smartly after braking. The same crossing in previously owned Audi A4 1.8T and Audi A4 2.8 (both without fly by wire throttle) could be safely negotiated without any acceleration delay. This situation is unacceptable and highly dangerous in normal everyday driving. References from audiworld.com forums it is apparent that there are many owners experiencing this problem. All have the Audi tiptronic transmission and fly by wire throttle system, not limited to the 2.7T model. Here is the link to the latest messages forums.audiworld.com/A6/msgs/304185.phtml also, consumer reports have noted the delay in acceleration when testing this car. Here is the link. www.consumerreports.org/main/detailv2.jsp?content%3C%3ecnt_id=302773&folder%3C%3efolder_id=97851&assortment%3C%3east_id=333137&bmuid=1066370138539 several other reviews in the U.S. automobile press have also noted the delay. Repair local Audi dealer is unable to offer a solution since their troubleshooting techniques only indicate a "no fault found" or "unable to duplicate" situation (several visits). Escalation to Audi headquarters elicits statements such as "working as per design, "safety feature (prevent over revving damage to engine/transmission)", and "system has to process a lot of data".

- Scottsdale, AZ, USA

During inclement weather driver must pump the brake pedal to stop the vehicle. Also, the brakes grab in the rear. Dealer replaced the brakes four times, but problem still exists.

- Munhall, PA, USA

Consumer stated while traveling on wet roads the brakes become soft. Once dry, the brakes grab. The consumer stated the front and rear brakes were replaced several times.

- Homestead, PA, USA

The vehicle shimmied severely when the brakes were depressed.

- Salinas, CA, USA