I also was running an 'out of the box' MP9 (TKI3) and the drive shafts are a well known 'quirk' that has a number of solutions (shims, longer shafts, different diff O/P cups). I only found this out after finding the same issues on my 1/8th electric MP9 a few weeks before and asking around various drivers, so I had time to check and prepare before the Pro-Line. Preperation is everything!
Yes it's a shame we all had issues with new cars, but my 1/10th fell to bits loads before it worked long enough to finish a days racing....and now never gets used.
These are just toy cars and like life you have to find friends and fellow racers that you get on with...regardless of who they drive for. But big race days are not the best time for many with lots going on.
Thumbs up for JQ
for helping you out on the day.