$30, let's you keep the LED & mute
http://www.amazon.com/Escort-D...tectors/dp/B0003NN83K/
If that's too much coin for you, then you could do the fuse tap method and give up the LED and mute. I don't like the idea of wrapping wire across a blade (I'm an automotive engineer and design the fuse blocks) ... when you wrap wire on a fuse blade, you exceed the width of the female terminal or busbar slot. You could deform or relax it, or scrape of the metal coating (usually tin). Plus, the chances of a short is higher if the wire frays or breaks apart and touches another fuse or wire or metal.
Make sure you have a voltmeter so you can separate the B+ fuse (always on) to the accessory fuses (on only when the key is turned to ACC/IGN). Alternatively, refer to the fuse label if it tells you.
Assuming you have minifuses, there are tons of ways to fuse-tap. You could spend some $$$ online and buy them.
$9, fuse tap with short jumper
http://www.amazon.com/Wirthco-...it-Mini/dp/B000CQI22K/
(There are other options which amazon will show in the viewed/purchased by other customers' section)
Lastly, you'll need to select the proper fuse value. I have no idea what the power draw of an Escort 8500 is but I would have to imagine that it's small. I'd go as low as you can (2A as bruceb said sounds pretty decent)
Make sure you lay out the extension wire to prevent a chance of shorting the wire out over time as it rubs with metal edges, etc. Remember that the vehicle is negative grounded so any short should blow your fuse.
If you're really in the spirit of things ... recycle your plug-in smartcord and turn it in to a direct wire!
http://www.scoobymods.com/diy_...ef85e8d7bf&p=15045