If you are going to have your detector in one car in particular, you want this. Hard wire it, save a cig lighter socket for something else (and clean up the dangling wire mess). Plus -- you can put the warning panel in you line of sight, but out of obvious view of a following cop if it goes off. It also allows you to put the detector in a better location (on your visor maybe) for extended line of sight and put the display into either very low or off mode (that observant cop again). Needs a good 2 sided piece of tape packed with it though.