You have probably checked the front drain holes. You also need to check the rear drain holes. (1) park on a slight incline. (2) poor a lot of water (apx 32 oz) into the track (check both passenger and driver side drains) that runs to the front/rear drains. (3) the water should drain freely through drain tubes that exit under the car near the rear wheels. On my 100 these are 1" long black tubes that exit from the car panel under the car between the bumper and wheel well on both sides, iirc. (4) remember that you cannot see the ingress drain holes from the roof rack, so you are just letting the water run-- only if the water backs up or fails to drain will you see a clog. 32 oz is enough to see water run out of the drain.I've cleaned them regularly...it's a bad design...