I got one on my Focus...Ford Racing. Came with a Goodyear belt.
It's made a difference when I've had to gun the car a few times. It's not a kick in the pants...but when you've got an auto with a/c going, you need all the help you can get.
Just note: I've heard folks staying away from UDPs if they have a massive power draw e.g. stereo system.
