The harness needs to be attached to rollcage directly behind the seat. It cannot be attached on any more than 45degree angle?? You think if its staight down and you have a crash the seatbelt is going to squish you down and compact your spine. This is the only way i have seen it done for a rally 1200 ute. The harness will have to pass through the rear steel section. there wouldnt be any room to have a rollcage inside the cabin .
Cheers Andrew