As Scott wrote in his build-manual the build is a tight fit.
I did not follow the order exactly as he described in which you should mount the parts, but I doubt that this would have made a big difference. (I'll try next time

)
In the end some of the parts would not align, but only just. I had to apply a bit of force here and there, also used a file on the three most rear bolt-holes in the chassis .. and everything went together just fine.
It sure won't have any loose parts as I have gotten used to when building, driving and racing tamiya-cars