Hehe...
You already have a relatively good car and fast and reliable engine. Also a good TX/RX. Spend your money on new wear/tear parts like your gears, etc. Get a few spares so you can play around with ratios. The get good servos to go with your TX.
Some other items like different springs, shock oil, etc.
If still got money, which I think you do
, get a car setup kit. And some proper tools.
There is nothing wrong with your current car. If it aint' broke, don't fix it. The NTC3 is still doing well in races all across America. The car is not bad. You just need to understand it better and improve on your driving.
Besides, you have already invested so much in it, like tools etc.
Just my opinion.
Maybe I've said too much.
I'm outta here...
!!!