I have never had water ingress problems - partly because I clear the drainage channels regularly of any muck or leaves when parked on my drive.
But I have had two ingress problems within a month.
One was pinpointed to a defect in the seal around the A-pillar (where the roof connects to the windscreen) and this was fixed under warranty
But now I have a damp passenger footwell which the engineer cant pin-point to anything. He checked the drainage channels (clear), seals (fine) so he dried out the carpet, did a water test, kept the car out in the rain, did a water test again and all good. So why was the carpet damp in the first place?
I can't help with this, unfortunately, but just wanted to post before Surge comes in here to tell you that MB engineering is perfect and it's your fault.
I had water drops come out of the ac vent with the top down on high humidity days ... enough to wet the carpet but not really do any damage. I also check my drains frequently as the convertibles with get water in them if they get plugged. Never heard of the A pillar issue though.
You're right Its probably only condensation from the windscreen (when I am clearing the screen and the air flow flicks drops of water onto the seat/carpet) or from the AC vent.
The engineer went over the car again and again and water tested it 3 times over 4 days and was not able to recreate the leak.
The A-pillar seal replacement was a defect and replaced under warranty.
This is not the seal around the glass portion of the windscreen.
This is the actual rubber/alcantra section on the inside surface of the A-pillar right round the two pillars and across the back of the windscreen.
A good 4 day job and then car in the paint booth to dry off under heat and then all the bits go back on.
These pics were taken with the top down and the drivers door open. The plastic is the flap that actuates when the top in opened or closed. You look in-between the top and the rear quarter, very small space. I'll take another pics later.
Edited to add: I went to the garage to look. Although I've only had the car since the beginning of September 2020, it sat at the dealership for over a year (!). Nevertheless I didn't think it would have any issues. I've never driven it in the rain (and we've only had a couple of days of rain in Southern California since I bought it). But I was wrong. There is debris circling the drain. I will clean it out when I find something that can get into that space.
Slideshow: A one-of-one U.S.-spec Mercedes-Benz SLR McLaren Roadster became even rarer after a factory-backed transformation at McLaren's headquarters.
