MSD-How are you guys hooking up your ON-OFF switched wire ?

I have it wired up with a relay like Rob and Abomber but in reality that wire pulls less power than the original coil did so hooking it to the factory ignition switch wire that goes to the coil is just fine as long as all the wiring is in good shape. The big red and black wires coming out of the box that go directly to the battery are what pulls all the current. I only ran mine the way I did so I could have a hidden kill switch to use like a theft prevention system.