Barry --

One quick thought.... On the 240, the windshield trim is only aesthetic -- it serves no practical purpose. There is a large gap behind the trim. Rain could enter anywhere around the trim, run down behind it, and leak in through a hole in the windshield sealant.

So the good news is that sealing the trim does nothing.

You need to get behind the trim and apply additional sealant to the existing black goop. If you're lucky, you'll be able to see where the existing stuff is leaking. Look carefully -- you may find rust beginning.

The bad news is that the windshield trim is held on by special (Volvo, breakable) clips.

When it stops raining, you'll need to remove the front seat, pull up the side trim, unbolt the front seat belt (lower bolt), pull out the rear lower seat cushion, and pull up the carpet. You'll find the underlayment will be soaked -- and that water will stay for months or years. It will absolutely rust through the floorpan, given time.