both the v6 and zetec will hit the limiter in 4th at around 6 grand i've hit the fuel cut off in 5th gear with my V6 mystique. same spot as 4th gear
the only "trick" i've hear of is getting up almost to the limiter putting it in 5th gear then turning on the cruise control and using the acceleration button on the cruise to "cruise" past the limiter. i haven't tried that yet.