i kinda doubt they would make a locking diff for a front wheel drive car, that would be very dangerous, and probably damage axles (unless the focus has stronger axles then i picture). One might be a tighter LSD than the other, but i seriously doubt one would be a full on locker.
"I am free, no matter what rules surround me. If I find them tolerable, I tolerate them; if I find them too obnoxious, I break them. I am free because I know that I alone am morally responsible for everything I do." ~Robert A. Heinlein