I am daydreaming about adding a roll bar into my car to mount a harness to and for some extra protection when I start tracking the car. Simple enough concept however my car has side curtain airbags that will want to occupy the same space as the roll bar if they ever deploy. How would I go about getting these two to coexist with each other?

So for those who don’t know my intent with this car is to drive it as my daily, autocross, and track toy for the next several years until the time comes that I have a newer car as my daily and this car is going to be built for stage rally or road racing. As such my idea is to design and fabricate (with help from someone with cage building experience) my own main hoop, backstays, harness bar, and possibly main hoop diagonals such that they are a roll bar for now but I can add the missing bars later and have a FIA spec cage in the car (with my luck they will change the regs and foil my plan). The intention to build into a cage later means I would be trimming the interior panels back a bit and putting the main hoop closer to the shell of the car than an off the shelf roll bar.

This is what my car looks like with the headliner removed. You can see the side airbag along the top of the windows. I would like to maintain the front airbags while it is still my daily and an airbag fault would mean I would not be able to pass the state inspection so the side bags need to either stay in or be spoofed.

How would a side curtain airbag react to a roll bar like the one in the lead image? What if the bar was within, say, 1 inch of the undeployed bag? Just idle daydreaming for now, I probably won’t be acting on this project idea for a while.