I've used it in one of my cars. It worked ok but nothing like a real diff would. I used the upgraded springs which was a noticeable difference from a friend who had the same car with the standard springs. It works like a clutch type diff so its not a great idea for FWD but works for RWD setups. From the looks of it, it would have to cause more wear on the spider gears of the diff but it worked fine on my car for the year I ran it.