13,172 units of the 2012 model year Audi Q5 crossovers that were built between 21 June 2011 to 9 December 2011 are being recalled in the US due to a defective sunroof glass panel, according to the National Highway Traffic Safety Administration (NHTSA).

"Some vehicles may be equipped with a front sunroof glass panel that is susceptible to breakage in extremely cold weather/temperature conditions," said NHTSA in its recall summary of the problem.

"Should the sunroof's glass break while the vehicle is in use, the falling glass could cut and injure the driver or passengers. It could also distract the driver, increasing the risk of a crash."

Audi first learnt about the problem from its dealers after a small number of vehicles came in during the 2011/2012 winter season with a broken panoramic sunroof.

The company performed an analysis which indicated that very cold temperatures could increase the tensile stress, between the front sunroof glass panel and the frame, causing the glass to shatter. I believe this is caused by the contraction of the glass frame caused by the cold weather.

Volkswagen Group of America said it is not aware of any claim of accident or injury caused by this issue in documentation filed with federal safety regulators. Audi dealers will replace the front sunroof glass panel free of charge. The recall is expected to begin on August 7.