Not sure if you have an old or a new Trillium
and how the windows/rock guards may difer.
We have a 1978 Trillium
4500. We haven't had a leak with the front window/rock guard combination. We have not resealed the windows
. DH did replace damaged fiberglass panels in the rock guard and remount the rockguard with butyl tape. Our rock guard has 4 screws on the side and a bunch up top. Those mounting screws/rivets are a place you could check for leaks
. Also the belly band. I attached a picture of the screws on the side of the rockguard. (We still need to get screw covers).
We have been in some bad storms camping and have driven through some good rains, but don't think we have experienced rain driven by 60 mph winds.
Good Luck finding your leak!