The plugs on the underside of the car are probably there to keep out dirt/sand/water or whatever from getting in from underneath. If you're not off-roading you're probably OK without them but don't go driving thru high water.

The cowl drain "nipples" only seem to serve to constrict the flow out of the cowl area and then get plugged up with debris and flood the inside. So it's best to have those removed.

I filed an insurance claim to cover the cost of the dealer drying everything out and cleaning the drains. The adjuster indicated this is a very common problem on German cars, especially Mercedes.

 

yeah on older w163 ML's.. there are two sunroof drains that have tubes that go down the a-pillar.. They connect to nipples in the front wheel wells just inside the car... as time goes on the tube shrinks and disconnects from the nipple and you get water in the car. Not too difficult to fix but having a pool of water show up really sucks.

 

For what it's worth, I have the same problem on my 2006 Touareg. But only in the summer.

It isn't the drain, or the windshield or any kind of outside water. It is huge condensation happening when the AC is on and hasn't been recharged in a while. Got a recharge. No more water.
Pierre.

 

I recently had exactly the same problem. If you take off the plastic inner wheel arches you'll finf the drain plugs, mine were blocked with silt and leaves. Unplug and STAND BACK!!! You won't believe the amount of water which comes our each side. Definately worth checking once a year.

 

Hi, new to this forum so please bare with me. I drive a 2003 cayenne rhd. It has just started to pool water in the drivers side (rh) footwell and behind me on the rear passenger foot well. Pushing into the carpet causes water to seep to the surface. I removed the 3 cill bungs but to no avail. Took off the drivers side plastic inner wheel arch. I cannot see a drain or pipe anywhere! Please send pics if you have them. Thanks neil