Hello
I have the same problem but I don't think it's the power because I am using a BuWizz Unit to power a single buggy motor.
Here are two images of my car I hope this helps.
https://photos.google.com/u/1/photo/AF1QipOIE8NofZNYGaO_4Yrfg20bRq4vz143enDgkBF0
https://photos.google.com/u/1/photo/AF1QipN7to0ZXWi-PMToY9wHfYD-4fI_NfVFCfVCeJxj