There is nothing fancy about my motor mount which i made with my dremel tool. It is based on an emaxx motor mount which i cut and drilled to fit in front of the centerdiff. It is screwed onto the centerdiff right where the brake calipers would normally be mounted. It is reinforced with an aluminium angle which is screwed to the chassis plate and the motor mount.
Looks awefull but does its job so far. (mounted onto the protos buggy chassis ... works on the br50 and mantis chassis too)