The windscreen should be sealed to the body independently of this trim piece, which does nothing the keep water out - its most likely there to reduce noise and for cosmetic reasons.

No leak til this day and I still have not replaced it yet. It looks much worse today than that picture posted 9 years ago! Since this is mostly a cosmetic piece as others have indicated - the windshield itself is sealed to the body independently of this trim piece, I may just leave it as is. My car is black and it's barely noticeable unless you know what to look for.

Helloooo ,phew good to know as mine is deteriorating fast, i an certain its the heat and use of a sun protector visor inside that covers all the windshield during summer, this protects the interior leather frm sun damage, but channels all that heat upwards too, so if it crumbles totally ya reckon i can get get way will installing sum thin weather strip in gully ?and or a plastic strip along glass ? Its a matter of time for the whole thing to crumble off

It’s a fairly easy part to replace.

Okee cokeeeee, toying with idea of some sort of weather stripping to run along glass although i reckon it will come unstuck due to heat, my x is silver so if you do take a peak it is noticeable....thanks though for feedback, good to know part is not for weather proofing

Just my .02, but I think what I would do is tape up the roof line and fill that shallow valley with black silicone. Totally waterproof and shouldn’t dry out too quickly in the sun either.

Just tape the roof line, fill the valley, wet a finger and pull along to smooth out the silicone- a nearly permanent fix, that will definitely keep water out.

It’s cheap to do it right. And silicone might be a pain in the ass if you ever have to remove. Depends on how good it sticks. But yea. I thought about that as well.

To be frank if it aint broken i won't fix it....if the strip is more cosmetic i wont touch but the silicone suggestion and even the replacing of the strip myself is something i will consider...

If the gap doesn't bother you (it hadn't bothered me), just leave it as is. Frankly, using silicone will make it stand out and look worse.

I looked at our Audi S3 the other day and it doesn't use that trim piece at all - its windshield just butts up the the top of the roof, with maybe ~1-2mm gap.

Whoops, clarification, I missed the fact we’re talking about the “beauty strip” on the front of the windshield, I was thinking this was the chunky rubberized window seal behind it. In that instance I have used black silicone behind the “beauty strip” and it’s totally invisible. I had a number of other things I was doing at the time and replacing the windshield seal wasn’t at the top, little black silicone along the top edge, again, down in the valley behind the “beauty strip” and my concern was alleviated for the time being.