Yes I am using a relay, the one provided by Hella in the 500 series driving lamps.
I tried wiring them without the relay (after many headaches trying to use it), running it diectly to the switch which probabaly wasn't a good idea. They worked for a while, then I blew the fuse attached to the power wire so I figured it was too much of a load for the switch/fuse.
I got some new fuses and am attempting to hook everything up again. Unless you have previous electrical wiring experience it isn't all that easy. Sure the diagram seems simple enough but it hasn't been a simple project for me, but it's probably just me.
For those of you who tapped into the low beam, where exactly did you tap it? I'll keep you updated on my progress because I'm sure I'll have more questions.