Here's another option- Tell him to stop crashing so hard...
For chassis strength, you might try a strip of 1/8"x2" aluminum from the hardware store. Run it along the entire length of the underside of the chassis, bent to the contour of the existing skid plates, and use longer screws to attach it. Or, just replace the skid plates with the aluminum piece. I don't own a Maxx and I'm not sure if it's even possible to do this, but I know it would add lots of strength to the truck for not a lot of money.
