I have a 99 GS300 that had a lot of popping noise from the sunroof. The dealer installed a felt kit to the sunroof to get rid of the problem. Unfortunately, there was not enough felt used to get rid of the noise from my sunroof.
I talked to the dealer and they told me to line the entire plastic trim surrounding the sunroof with felt. I bought some felt at one of those fabric stores that has the sticky back. I pulled the plastic trim from the sunroof with my hands......sometimes it ferlt like I was going to break the plastic pieces but they eventually came off. It took me at least a couple of hours to meticulously cut and piece the felt into the entire inside of the plastic trim. I was careful to leave the felt out where the plastic pieces joined together.
All of the tedious work paid off because the sunroof never made any more noises. The felt gets rid of all the loud popping/snapping noises that you hear when you drive the car.
I also had another problem with the sunroof because I was hearing road noise from it. When I closed the shade the noise went away. Since I just bought the car the dealer told me to bring it in and they would fix it. They said the drain line for the sunroof goes to the rear wheel housing and that's why you hear the noise. I'm not sure what they did......I think they either insulated it or slightly relocated the drain line which got rid of the road noise.
Right now my sunroof is just like I want it......absolutely no noise coming from it.
