Dan Cook's Rally Car Cage - Rear Cross Member Tie-in, Top View
The rear suspension cross member mounting points are bolt-in studs. Here you can see the end of the stud inside the vertical tube. The tube had a washer welded onto the end of it before being bolted back together into the car. A reinforcing plate is welded around the tube and to the car's sheetmetal. Plate gussets are welded to the rear of the main hoop and cross bracing to tie the rear suspension to the car’s rollcage structure.