I've had repeated problems with warping rotors and
my mechanics are at a loss how to proceed. any
similar situations out there?

try a good set of quailty ford motor company original equipment pads and rotors. We have noticed on the older sables that the aftermarket equipment tend to not disapate heat quick enough and cause rotor warpage.

Had a Caddy that had that problem, the engine idle too high and the guy had to ride the brake more. Had another car that the brake lines (hoses to caliper) bad, causing pressure to remain and cause a drag.

Thanks for the recommendation. Do you work for a Ford garage? Is this something you've seen often?

A set of brembo rotors and wagner pads do a better job than the fomoco ones do,sorry.