Cages are 100% street legal if their of proper build and you can prove it. And once proved that it is of proper build the MTO will legally safety the car with the Cage in it and then a cop cannot do a damn thing thing. When I say “proper build” that does not man a Cusco Cage since they wont pass.
Theirs a bit more too it thou, but a properly built Cage is indeed Street Legal. As for Insurance… have fun, and the only way around them not covering the Cage is to have the Car appraised “because then tech, the Cage becomes part of the car” and then the Car is insured on its valve, thou you tech just pay an increased premium to be legally aloud the Cage.
As far as a Harness Bar goes… Not Legal. Its either a Cage or you weld in plates to the floor “top and bottom” and then attach the harness to the plates. Reason for the plates top/bottom is to sandwitch to floor which ensure the harness cannot be ripped outta the floor since it would have to also rip throu two 3/16’’ plates + the floor.
Lastely… Harness Angles need to be 100% to spec based on the Seat/Shoulder height of the driver… if their on the round angle and you got into an accident, it could cause your spine to compress resulting in one of many things…