Nice work Jim,when I built my twin engined chassis which is featured on scratchbuilt .com I used counter rotating armatures to cancell out the torque reaction ,but this is probably not as important in a magnet car . I hope it runs better than mine did( which sits on the failed experiments shelf in my workshop).If you get it back inone peice why not send it over to us in the UK for an attempt at The scale sound barrier in the slot tech mach 1sprint it loks lke it might be a contender.
Graham