Get one Ryan. It will help prolong the life even if it has a lot of miles on it.
I still have to get one, and should have a while ago since I'm modded now, but my tranny (knock on wood) seems to be fine still. I figure winter is coming and I'm not going to drive it hard so I should be fine for a while. I just hope mine doesn't go before I can afford to fix it.
Pegs the boost gauge. Haven't lost a race yet. Can't do any real times yet, but I know I get 10lbs. or better of boost. I STILL get a rush when I step on it.
I can't wait till I have a Boost gauge.