@NarimanAsgharian - Sorry this reply is late to the game ... hopefully you've installed it with success. As for what I'd do, if not using silicone, I'd just use some grease. It will help it seal as well as help keep it in place during assembly. The only downside to using a thin coat of RTV is cleaning up what's left if you ever have to replace it in the future. Really, that isn't too hard of a job, but can be a PITB if in awkward places.
Nonetheless, some grease (just any high pressure grease or even Vaseline) will do you wonders.
@Catija - Something to remember about when the insurance company wants to total your vehicle ... you don't have to give them back the vehicle. You can always take the vehicle as is and they can pay you the difference. If the vehicle is completely usable and you could care less about hail damage (as long as the damage doesn't affect safety), take the money (and vehicle) and run.
Anecdotally, I told the same thing to my Mom. Her car was paid for and got hail damage. The insurance company was going to total it (for obvious reasons). She was all worried about getting a new car (she is retired and lives on a very strict budget). I asked her two simple questions:
1) Does the car still function properly? (Her answer: Yes) 2) Do you care how it looks? (Her answer: No)
I told her, then don't worry about getting a new car. Keep the car and the money the insurance company has given you and consider the vehicle has paid you back for whatever you've put into it.
She still has the same car, and this is quite a few years later. I don't know how it looks (never saw the damage), but she's not overly worried about it and it still gets her down the road.
The amount the vehicle was worth at the time of the damage was something like $5k. She kept the car and got ~$3500 from the insurance company. The big thing was, if she had taken the $5k, she wouldn't have had enough $$ to replace the car. It would have only made a down payment.
The Pitstop
The Pitstop