The way I see it when it comes to building a kit is why rush it. I know a lot of rc guys that will say they built the kit in 2-3 hours but I could care less. I take a couple days to build a kit because honestly, the build is most of the fun. I like to take my time and make sure everything is right to my standards. I make sure there are no binds, leaks, all plastic flashing and burrs are smoothed with my dremel, etc. The mugen car goes together well. The only advise I can offer is assemble your diffs using the s5 orings from tony's, and mobile 1 synthetic grease. Also check all the hinge pin holes as a few of mine needed a pass with the reamer. Good luck.