Check the Water Drain for Debris

-- Open the glass panel all the way.

-- Drain the water from the guide rail near the open glass cover -arrow- into a commercially available measuring container -1- out from the vehicle interior.

Fig 1: Drain Water From Guide Rail Near Glass Cover

Courtesy of AUDI OF AMERICA, LLC

Make certain that the water divides in both directions so that it can flow out again from the A-pillar and from in front of the rear axle.

-- Repeat the process for the opening on the opposite side of the vehicle.

NOTE: If no water flows out from the appropriate areas, clean the water drain. Refer to WATER DRAIN HOSES .