I just had the same problem, I'm in maryland.

what I did was remove all that plastic trim below the windshield in the engine compartment.

There was pulled water in the cavities, i use a mity-vac to draw off the water then vacuumed the leaves out to open the drain.

The cavity that filled was just in front of the trap door that sits above the blower motor for the HVAC.

I would also remove the panel under the glove box, take off the plastic panel (held on with slides ) under the blower, also replace the cabin filter which is beyond a seperate slide mounted cover.

There is a post on this forum or was it at www.mbca.org that had photos of the plastic trim below the windshield that needs to be removed.

In my case, and it seems for you also this isn't an issue with the sunroof drain or the plug in the rocker panel just aft of the passenger side wheel - though that plug should be probed or removed and then replaced after feeling for any debris.

If you need step by step instructions and you have the proper tools respond back.


As Ilumvils mentioned -my technique is a bit different- if you pop off part number 202-831-01-58 which is a SCREEN AIR grid just to the left of the mono-wiper and rest on the windshiled (there is a drivers side screen opposite), it will give you access to the cavity that gets clog. I found I needed to remove the engine width trim underneath that (held on with ten screws I THINK ) to vacuum out the debris, The second panel is a bit tricky because you need to remove an overlapping particl disc that fits under the mono-wiper arm base.