The car stalled while driving. There were no warning lights or indicators before the failure. The car was unable to be restarted so it was towed to a mechanic. It was discovered the car was out of gas however the gauge read there was still a lot of gas in the tank. We then took the car to an Audi service center and they informed us it was one of the gas tank sensors that was faulty. They replaced the first sensor and charged us $1k and that didnt fix the problem so they contacted Audi and were told it was a faulty second sensor inside the gas tank and the only fix is to replace the whole tank. We opted not to replace the tank at this time. After further research I found that the sensor we had replaced is recalled on other Audi models of the same year recall #22V155 I believe more investigation and recall is needed to include the Q series Audis as well as further investigation into the gas tanks internal sensor that requires a replacement of the whole system.