So I have a little POS radar detector and I'm upgrading to a Passport 8500. I have my current one hardwired to my cig lighter with no problems (I just tore apart the power adapter to two wires).

However, from looking at hardwire kits on ebay and such for the 8500, they all involve wiring to the fuse box. Why is this? Isn't the cig lighter fused already? I would think that wiring to the cig lighter would be a LOT easier and more convenient in that case, but is there something I'm missing here?

 

I have mine hardwired to the fuse box under the dash. the ground wire I bolted to the closest metal place that had a bolt and the positive one I plugged in on of the fuse slots that is not being used. I also checked with my multi meter if the slot only worked with the key in (so I don't end up draining the battery).
I ran the wire completely hidden. Only like 1.5 inches is sticking out and thats where the detector is. Also my detector is on the left side, right by the A pillar. I hate how it looks in the middle of the windshield.

 

the reason the directions say to tap power from the fuse block is so that you won't over load and blow the cigarette lighter fuse, which could happen if you actually use a cigarette lighter for cigarette lighting. the cigarette lighter is fused and it is "dead" when you turn off the car and remove the key, so if you aren't using the cigarette lighter for anything, go ahead and use it for the radar detector.