I decided against using a switch to activate the light because when an oncoming vehicle aproaches and its time to turn the highbeam off, I just want to deal with one switch (the standard highbeam/lowbeam switch). I have considered placing a switch in the wire that will run from the highbeam line to the relay. Then I could use my highbeam without the extra driving light if I wanted to. I'm just not sure why I would want to.
I got the kit at Princess Auto in the surplus section.
I think princess auto is a canadian only chain.
They sell mostly tools and a bit of automotive stuff.