Quite a good glue. It was used to attach a spoiler without screws and it did the job just fine. It is not a particularly malleable product so you can't spread it easily, but it dries quickly and can be cleaned off surfaces even right after it dries. It has been tested on a national road at 150 kilometers and the spoiler holds up just fine.

Because it was my first time using windshield adhesive, the following things impressed me: 1. It had a metallic protective cover that I had to remove in order to use the silicone gun. 2. It requires a strong gun as it is thick and requires a lot of force. 3. Definitely wear disposable gloves and clothes that you don't mind getting dirty.

As for the application, I don't know how to advise. I simply tried to patch up the windshield - there was no damage - because it seemed like the car's roof was getting water from there. But in the end, it seems that the door's rubber was the culprit.

Because it seemed troublesome to me, I would say get relevant advice from professionals or pay someone for such jobs.

Just my personal opinion. Good luck!