Im 99.9% sure its just excess water that leaked out from your front window and hood area. Especially after a wash. Its just like how side mirrors and pool water inside them and leak once you get going. The only difference is; the road dust is much closer to the bottom of the car so it attaches to the water leaking down in that corner and stands out much more than a water drip down your door from the mirror.

 

mine did it when it was new for 1st few months...and seems to have stopped. This at about 2 weeks old at worst. This the driver side on a UK car and I just checked a picture at same place on other side ( our passenger ) and no marks at all I could see . This as I recall was the "norm" perhaps not hard fast .


( Scotland , near Aviemore )

 

In the 991 community, we see this and everyone swears it's when the washer fluid reservoir is nice and full and that's what's leaking out. I've never experienced it because I don't use my washer fluid much at all and in three years of ownership have never topped mine off.

 

to add to my posted picture ....washer fluid I always keep topped up ...and it on the UK passenger side ( USA driver) which as I noted does not do this, but my driver side does. Just a thought .

 

Not even the Targa is immune ....

 

Never noticed it on mine, but I use an Air Force Master Blaster after each wash to blow out everything from crevices, etc on paintwork. Seems to keep it from occurring.

 

Me neither. I have noticed that when I wash mine, a lot of water gets trapped in front of the doors and behind the side window trim in the rear and requires much air blowing to get it all out so it doesn't drip (I use a Big Boi Pro).

 

+1 with the Big Boi Pro. Love mine.

I believe @Esoteric_Detail just received a shipment recently as well if others are interested in a quality car drying system.

 

I don’t experience this. My 992 has always been hand washed and blown dry — it’s ceramic coated.

 

Just to close this off, it's definitely washer fluid. Only happens on mine when I actually use the windscreen washers and I guess is obvious on light coloured cars. Why there's black coming out with it though who knows, it looks more than just road grime being flicked up.

 

It really is from the windshield washer reservoir. Run some of it out and it should stop.

 

Maybe my reservoir isn’t that full, it only happens on my car when i use the washers.

 

It’s drainage from the door cavity - can see it running after the door is opened after.the car has been in the rain

 

Try this: Wet the wiper blades and then run your finder along the squeegee portion of the blade. The sides of the part that touches the windshield. Highlighted in red in the attached picture. You'll find your finger tip probably comes up with a bit of black residue on it. The Wiper Blades deteriorate over time. When you operate the windshield washers this not only cleans the glass, it also cleans the squeegee portion of the blade. If you live in a smoggy area (like we do here in L.A.) the high Ozone (O3) concentration in the smog hastens the deterioration of things like wiper blades more here than in areas of the country without so much smog.

Anyhow, this deterioration of the Wiper Blades is the primary source of the "Door Dribble" you're seeing. For those truly OCD afflicted, you can reduce it by replacing the Wiper Blades more frequently. Or, when I wash my cars I give the Wiper Blades a bit of gentle soapy attention and that seems to take care of things. I also (usually) have to replace the wiper blades on all my cars once a year simply because they deteriorate here over the course of our spring and summer months in our lovely dry and smoggy southern California air. Between Halloween and Thanksgiving is usually a good time. That''s usually just before the rains start here.