I recommend getting one. My SRT is not modded. Keep in mind it doesn't completely eliminate the need for a throttle resets, but it definitely increases the time between resets for me. Get one, you won't regret it. I found a used one from a member on mbworld - it was the original version for the Limited (non-AMG). It works fine and it was only $125. Unless you have your heart set on the adjustable booster (in which case go ahead and assume you are going to pay retail or close to it for a used one), look around forums for a used one.