This is for a automatic w204 or 2008+ C300 model (im pretty sure it will work with c350 also) and it has only been installed for 2 months. If you hate that lag in the pedal response time than this is the mod for you. It improved the driving experience all around, and you will really never have to use the eStick to downshift in order to pass on the freeway. The only downside is that since it stays in the higher rpm range longer it needs more gas. I love to drive fast but I also love not spending money on gas so this is why I need to get rid of the temptation. I originally paid $330 for it and willing to sell it for $250 or best offer.