Just for the record, I have an '01 Trooper LS that has had the same problem
for about a year. When I asked the dealer about it a year ago, they said it
was the brake light switch. They didn't offer to replace it under warranty,
and implied that they all do it sooner or later. For what it's worth, I
still haven't been able to get rid of the squeak.
As a side-bar, the shoulder belt anchor in the door post has a similar
problem. WD-40 helps for about a month, then it's back. Irritating as