there's one on ebay now for $125 & I found an aftermarket one (took a little looking) for $100 but unfortunately I can't remember where.

70 Roadrunner convt. street car 440+6, NOS, 4-spd, SS springs '96 Mustang GT convt. street car '04 4.6 SOHC, NOS, auto, lowered "Officer, that button is for short on-ramps"