Tri-Bars. They are available at Mustangsplus (
www.mustangsplus.com). Mustangs and Fords recently did a terrible article on them. They just plugged them in. Unfortuantely, the old mustang wiring (that runs from the battery, to the fuse box, light switch and back out to the headlights) can't really support all of the current that the new halogen lamps require. I added two Bosch relays that basically operate off the existing low/high beam circuit and send direct battery power to the lamps (through a fuse, of course). Below is a picture of where I installed the relays. the location is behind the passenger side headlight bucket.
http://albums.photopoint.com/j/View?u=1571478&a=12409371&p=45514478&Sequence=0.jpg
Steve Leslie, 65 coupe in restoration. 302, toploader, A/C, disc brakes, bench seat
http://albums.photopoint.com/j/View?u=1571478&a=12535662&p=46267978&Sequence=1.jpg