On my Losi 2.0 truggy that bracket caused the motor to be at an angle to the axis of the spur gear resulting in them self destructing (a Robinson pinion and Robinson extra wide spur). I removed the Losi support bracket and made a support for the back end of the motor out of Kydex. This serves the same purpose as the Losi part but was fit to exactly support the motor without messing up the gear mesh.
BTW, using those button head screws to hold the motor is about the worst thing you can do. They will dig into the aluminum and let the motor move around as the aluminum deforms. I've seen this before on a car I bought.