The 1996 SHO (and, in fact, all new Taurus) exhibits a howling noise at highway speeds approximately 65 mph and above. The fix for this problem is RTV the cavity or to install a piece of foam rubber tape between the seal and the windshield. This will keep air from getting under the seal. Your Ford dealer should be aware of this fix.
At lower speeds a howling sound could be caused by air leaking past the door seals, causing the seal to buzz against the roof. This is easily corrected by the dealer.
Francis Chiu writes:
My '96 was "fixed" by the previous owner, and the RTV is starting to bubble up the paint
around the windshield molding. According to the dealer's body shop, they've seen quite a few Gen III with the same problem. Fortunately, Ford is willing to pick up the $500 bill for repainting. But I'd think twice before filling the gap with RTV...