I don't know the status of CARB approval for the TT. That is exactly why I originally went with the 4.0 Whipple.:thumbsup Fully CARB approved and really is fantastic. :thumbsup:thumbsup I highly recommend it for anyone on the fence. My problem is it wasn't a TT and that is what I always wanted from the start! Kalifornia is what talked me out of it. After the first year of ownership passed I started to realize, (rationalize) a few things. My car spends most of it's time on the roads of California in a trailer(her idea actually). I know many get the pleasure of driving from point A to B, but with the trailer we can bring all our stuff and enjoy driving the car at the events - and don't worry about it between. At this stage we can only afford this one and want to keep it nice for as long as possible. Next I realized I had a vision of what this great car was to me (TT) and I did not want to compromise my dream, (as if the Whipple could ever be considered a compromise):rolleyes (Thanks Jason,Shelby, Chip, Torrie, Ray, etc...) Fortunatelly, my wife has been endlessly understanding and supportive of this all. (I think she actually loves this as much as I do). The last factor for me is I have an out of state address and have limited time I want to stay in California. I did keep the stock components just in case this changes. (The sad thing is I spent extra to get the cat system and it will pass emissions - except the ridiculous visual requirement in Kalifornia.) :ack Again, stock stuff retained...