The method used to reduce the castor angle is to rotate the crossmember towards the front of the vehicle by providing a precisely stainless steel packing piece between the front crossmember fixing points and the underside of the chassis leg. (V8 Register of the MG Car Club)

The crossmember comes removable in some cars while in other units, they come as a part of the car’s body. But this doesn’t change the purpose of the crossmember; whether removable or fixed, crossmembers are installed in the vehicle to provide greater ground clearance which is very important especially in going through rough trails. (Auto Parts Wholesale)

The center laser projects up past the front of the chassis and can be used to align with the front crossmember, chassis front stub, and front tires. (Circle Track)