I really enjoy my M-Four. It's a great car. The only thing I needed were some Kyosho o-rings for the diff (oil leaked from axle cup side ) and some Green Slime as well (leaked from the belt side ). That plus running AE diff oil 3K and 5K, no more leaks.

There's a M-Four thread if you want to check it out. I got most of my info there when starting out. You also need to get the 2820 sized 2S Lipo's too unless you can find short shorties to fit under the belt + servo relocation kit Tamiya has available.

EDIT: I bumped up the M-Four thread for you.