I was doing maintenance on car. Had new tires and alignment done. The alignment tech found rotted out rear sub-frame underneath plastic covers. Said that it was unsafe to drive. Had it fixed there. Mechanic had another Q5 on rack, he said it had exact same problem. Tried to find used parts, ALL had rot through the frame. Found a part in Texas that was clean and bought it to replace. Asked Audi USA to reimburse me for the cost as they have a supposed 12 yr rust through warranty. They told me no because it only applies to body parts and that I didn't get it done at an audi dealer. The plastic cover is the issue as it keeps the moisture locked into the part. Audi A6s have the same frame but no cover and they don't rot. This is a dangerous situation and Audi is looking the other way.

- Oxford, MA, USA

The rear subframe has plastic "stone guards" to protect the frame from being damaged in off-road conditions. Where these stone guards are attached, the subframe has rotted/rusted large holes. Water and salt from winter seasons can get trapped behind these guards. A subframe on a vehicle at this age should NOT have complete holes rotted through. Let alone a vehicle brand such as Audi, known for quality. The rear subframe connects the rear suspension and AWD drivetrain to the unibody of the vehicle. This is a major safety concern. It has not been inspected by the manufacturer; my Audi dealer denied this could happen. I am part of a few Audi groups/forums with others facing the same issues, and Audi replacing the subframe under the corrosion warranty. This is a widespread issue amongst the forums. There are no warnings or symptoms as of yet. I noticed the holes 3/17/24. The vehicle has been somewhat sufficient to operate. I just don't want to be traveling down the road with my family in the vehicle if the subframe collapses. I am afraid to fully remove the stone guards as others on the forums claimed that Audi would do nothing for them after removing the guards. Being that they are "protection".

- Valparaiso, IN, USA