Is it though?
You've put a load of steel pipe inside the cabin of the car.
Unless you're strapped in with harnesses then you can float about a fair bit and batter your head in on the random pipework you've installed in your car.
That's why race cars have bucket seats, harnesses and rollcages, not just some pipework inside the car.
It's also why race drivers wear helmets.
It's also why race cars have to have expensive padding strapped to the pipework around the driver.
You've just put some steel pipe inside your car. It's a pretty terrible idea, all things considered and not at all safe.