This is the third time I'm installing a rollbar.  Actually, I have installed a HardDog bar in a NA, NB and NC.
I wanted the following features:
- Single hoop
- Max height but still compatible with soft- and hardtop.
- Harness bar
- rearward bracing
- double diagonal in the hoop. Mostly for looks I guess..

 I ended up with HardDog again since Boss Frog don't have a single hoop bar for the NC (yet?) and cheaper than AWR.

Install was complex and took more time than expected.  The instructions were sparse and I now understand why their pics in the instructions was taken without a softtop or seats in place. It was extremely tight to get things in place with all the plastic trim.  I will say a NA/NB install is half the job.
Espechially without the harness bar as that requires additional cutting for reusing part of the OEM bar.

Some pictures:

New bar:


The bar is covered under a lot of plastic covers. There is a lot of space under the bar compared to NA/NB.  On the PRHT version this is supposedly where the foldingmechanism is located.


The starndard bar is mounted to the chassis via 4 points + 2 small sidebars.
Thats is actually not bad. If it had been taller it would be a pretty good stock bar. It is certainly not just a style bar.


Here is a comparison between the M3 Sport and stock:

One of the hardest part of the job was to bend/cut the side covers shown to the left of this pic to make room for the rearward braces.  The metal is thick and very hard to bend with what I found in my toolbox combined with the cramped space.  I ended up using my angle grinder.  Not a good feeling when sparks are flying all over the place with the gas tank inches away...


Getting the rearmost plastic covers in place was a b**** but I finally got everything together.  The double diagonal required a lot of trimming of the plastic covers.  They also make the windblocker useless without serious trimming of the upper edges.

I'm satisfied with the end result but would have liked it to be wider. That would require relocating the stock seat belts which I guess is a big deal on a new modern car.  I like that it is a lot safer for regular driving without a helmet.  The M2 bar with a stock seat was very close to the head compared to this.