Pick up an add-a-circuit and connect it to one of your accessory fuses, e.g. radio or cigarette lighter. This way they're switched with the ignition. It's been 9 years since I did the install so I can't recall for sure which one I used. The LED's have since quit working - still getting voltage to them so I just need to replace them.
There's also a convenient bolt for grounding nearby if you remove the kick panel trim on the driver's side.