RudyZ

If you get the "extra force" struts from ebay, be aware that closing the trunk lid (from full open) also requires "extra force". BTW the trunk lid does not "spring up all the way up" with the extra force struts. USA made.

Had a similar problem with a used Navigator that I purchased. Went through all the prior recommended troubleshooting. No luck.

Went to an automobile glass business in town. They popped the surround trim and inspected the sealing bead on the windshield perimeter. Whoever had replaced the windshield prior to my ownership did a poor job of sealing the glass.

Couldn't repair so a replacement windshield did the trick for me.

Good luck.