^ I'd recommend using the search function to answer typical questions like Rensuhlo said
But to answer it here, I use a Uniden R8 and it's great and has saved me from several tickets already (not driving like a dumbass, like doing 15 over on a highway or empty back road and knowing Tampa Bay police and Florida state troopers are absolutely ravenous dogs for handing out tickets to sports car owners) - I do not have it wired up fancily or hardwired though just through the included cable hanging freely.