Does anyone know how to adjust these dash vents? The dash-to-windshield rubber bead is sitting partially over the vent, which can't be good for the rubber when you turn the heat on. I can move the vent but I can't seem to make it stay where it should be. The nuts on the underside of the dash are tight, but there still seems to be some play. I know this is nit-picking but I hate the half-assed look.

Anyone?

Those upper vents aren't really ajustable, you bolt them on and that's it. Try pushing the seal lip behind, that's pretty much how it works.

Yeah, that's what I gathered from a little more tinkering. The old seal was so old it fell apart like a cookie when I removed it.

I believe that you need to first install your dash top, then the rubber seal you are working with. Mihai is correct, just push it down ahead of the defroster vents. Then you should install the new windshield. The defroster vents are "clipped" with really big strong wire clips onto a housing under the cowl that is part of the vent system. The factory had a foam gasket that was placed over a "locator" ledge that was held up against the cowl area. The defroster vent did not in and of itself "bolt" into place, and the foam "gasket" kept it from vibrating against the bottom of the cowl area. If you are "totally brave" or "nuts" you can remove the entire vent housing from below the cowl and replace the foam gaskets. Porsche used a lot of foam rubber as vibration dampners, and in a 30 year old car, most of it has long ago turned to dust or is so flattened as to be useless.

Good Luck!