I agree with Ashton, you shouldn't need a very big hole just enough for a single 18awg wire to go through and put a switch in series with the coiul on a relay to switch on and off the lamps. You can find a relay kit at any autoparts stores for 10 to 15 $'s or depending on what lights you buy they may come with a relay / switch kit, my PIAA's did.
I have had a couple problems with mine between stress cracks and the reflective coating peeling off of them, and they are by far not the cheapest ones on the market either..... But PIAA is really good about replaceing them, they have a lifetime warranty even..... I have a set on the way to replace mine now.... here is what one of them looks like now....
