I have found the actual source of the leak and fixed it. Sorry, no pics yet, I do have a couple, just taking a break from working on the thing all day today.
So one of the three hinges on the vent had cracked off and was no longer attached to the vent frame, but was still attached to the plexiglass. It lifted off and created a nice area through which water could easily get in.
It's my guess it cracked due to several reasons--
* Poor design, thin plastic hinge on the windward/leading edge.
* Likely a strong headwind on the highway over stressed it and busted it, no scratches or signs of a tree branch impact.
* Age - my TC is a 2012, the poor design had a very thin amount of plastic actually holding the whole thing together.
The repair involved taking what was left of the hinge, which still had a fair amount of plastic left, drilling 3 holes in it, and screwing it into the TC roof, then adding epoxy that to the original vent frame. It is now far stronger than the original way they had it. Next, to reinforce the remaining hinges, drilled a couple holes, ran screws into them... then two entire tubes of dicor to re-seal the entire vent and rubber roof to front cap seam, and liberally covering the new screw heads.
I bought 5 of those aluminum strips AnEv942 posted, with endcaps and a couple rolls of Dicor Butyl seal tape. I have the drawings from Eagle cap on the stud/cross brace spacing, so now to locate those and put the aluminum strips in.
