Looking for advice: Kirk Racing 4-point bolt in roll cage install

[OldRanger]

Does anyone on the board have comments on how to handle and/or improve the marginal fit on this cage for the rear legs?

How about sharing pictures of an install that is working/acceptable for you?

(Note: I realize the drawbacks of this option. I did an exhaustive search for available products, and I was determined not to rely on custom fabrication and welding at this point in the process. This seems to be the preferred 4-piont option for Bimmerworld, and given that I'm an East-Coast(er)...it make sense to source from a manufacturer in this region)

[STAATS]

Not my video - but just doing a quick google there is plenty of Youtube vids/DIYs and messageboard walkthroughs (of E46Fanatics origin and the like). Here's some examples:
Installing the Racing Half Cage - BMW E46 M3 - YouTube
Kirk roll bar review | E46 Fanatics Forum
In both of these at least it looks pretty clear the fit of the rear legs isn't that great.

I know this doesn't talk directly to your situation but for reference there is an Australian company that do bolt-in cages, half, full and everything in between, meeting various different levels of Motorsport Australia regulations. Due to their membership in the FIA, these designs should be aligned to FIA regulations and hence useable internationally (although check your local regulations)
BMW E46 - 2dr Coupe - AGI ROLL CAGES (agi-precision.com.au)
I have ordered their half cage as part of my Clubsport / Tarmac Rally build (only built for Regularity / TSD classing hence not full cage for Open Competition categories) and will provide feedback once installed - I can't speak for it yet but I know all these cages are designed and built off 3D scans which they then develop a design and jig from to build each one, so I am hoping for a solid fit.

[bigjae46]

Ratchet straps or a come-along will fix fitment issues…to a point.

[OldRanger]

Ratchet straps or a come-along will fix fitment issues…to a point.

That idea speaks to me.

I've also wondered if Kirk is just smarter than the rest of us and that somehow torqueing it into place with a bend strengthens the overall structure somehow. Ya know, kind of like a southern US version of Larry the Enticer in 'how to get your sled running minty'. "Those are f'ing torqued!" (as he turns in spark plugs with a pipe wrench).

[OldRanger]

Not my video - but just doing a quick google there is plenty of Youtube vids/DIYs and messageboard walkthroughs (of E46Fanatics origin and the like). Here's some examples:
Installing the Racing Half Cage - BMW E46 M3 - YouTube
Kirk roll bar review | E46 Fanatics Forum
In both of these at least it looks pretty clear the fit of the rear legs isn't that great.

Thanks for the links; I like the Vorschlag pictures. It's disappointing they dont show a step where the cage is bolted in prior to reinstalling the seat.

I will be installing soon, will take whatever advice accumulates in the next few days, and post up some ideas afterwards.

[OldRanger]

I want to share a couple pictures of the cage installed in my car. This is the version four no sunroof. Take a look at the position of the bottom legs, in this placement the rear legs also fit quite nicely without much effort

[OldRanger]

So - I have a few comments along the lines of “advice” for others:

1) Remove (cut off) the wire loom anchors on the wheel wells. They are in the way.
2) Drill one hole at a time in each leg and check your work with the base plate. If you make a mistake; address it before you drill a second or third hole in any given position on the cage
3) On the wheel well positions - drill parallel with the bar and the direction the bolts will go through. This is NOT perpendicular to the foot of the bar, nor the wheel well surface. While it might seem intuitive to drill perpendicular to the foot, the dimensions will be wrong for the bolt to make it through the base plate on the other side. This will also remove a bit of material on the bar that helps when you insert the bolt.
3) Install the cage without the rear carpet in place. I’m speculating how difficult it would have been to try and get the front legs in the optimal location and dealing with the carpet/padding at the same time. I have seen that approach by others (YouTube)