Rovan 152mm Drive Shaft & CV Coupler

First time I used the Rc car it broke the drive shaft pin. Now every time I use the rovan 4x4 Bolts and the part it holds are constantly falling off and lost to the dirt or grass. I’m sick of it. Nothing seems to be tight I only get like 3 ,400mtr loops on a grass field before the gearbox screws are gone from the underneath,or the engine mount screws are gone. Now I’ve only used it 3x and don’t want to replace bloody screws and bolts every time that I want to use this 4x4 rovan truck. I’m not very impressed by this product.