I attached them to the car using water-proof dubbel sided tape:
It doesn’t look too bad imho.
I went for a test-drive too. And I think there is less noise, but it is hard to judge it just by ear. I still hear wind-noise, but now it comes from the rear view mirror (I tested it with the mirror folded in, and the sound was less), and from other sources. I think the place where the window meets the roof now produces the most sound… not much to do about that… 🙁
But I will be looking for another mirror. The problem is, I want to mount it to the stock mounting place…
All in all, the raingutter fillers weren’t hard to produce, it only took a lot of waiting… waiting for the glassfiber to harden, the filler to dry, the paint to dry. And a lot of sanding.
I haven’t tested the added top speed yet… and I won’t… 🙂