I replaced my Harness bar with an Agency Power Roll Bar with my Daughter. It was tricky, The seats had to come out and Mirror removed....if you have a sun roof you may screw up the Alcantara Headliner a bit when I rotated the bar back. I would have had a sheet orsomething up there had I known but the car is for the track so not too worried. Total time I am guesing was 4 hours....spent a bit of time lining up bolts.

 

Looks like even the OEM bar has a curve in it at the base allowing the seat scoot back a little further the DAS bar does not.