Another Radar Detector Hardwire ?

So i'm trying to hardwire my new whistler radar detector. I bought the kit off their website, which seemed easy enough. I did an install on my old integra with the same connections, one to the fuse box, in a spare switched slot, and the other a ground. I have the wire ran but the problem is that there is no spot in the fuse box under the dash for the plug to go into, plus finding a ground among all the wires could be tough. Is there another fuse box under there that i am missing? I thought the fuses would be the average size ones, but the fuse slots, that are all taken up anyway, are really small. I think i might just tap into another wire that is hot when the car is on. What wire should i look for?
Here is a pic of the wire that i have

Anyone?

I bought it because if i want to take it out and put it in another car all i have to do is unplug it and move it into another car and i still have the cigarette adapter, it was only 10 bucks anyway. It was supposed to make this install much easier, because i live in an apt complex, but didnt end up doing that at all. But the problem is that i dont have a test light, so finding a switched wire becomes a little more difficult.