For our purposes the seat belt mounts just need to be 'secure' to be legal.
To be honest, if you skid into the path of an artic it doesn't matter whether you're riding a unicycle or driving a Range Rover, you've had your chips.
As part of my previous life I had to clear up the wreckage of aircraft from both sides that'd been shot down in the Falkland Islands. If nothing else, ejection seats have 'king good seat belts and
they were almost always intact. Sadly, the pilots hadn't always fared so well...
So, build and enjoy your own car. Put the best harnesses in that you can manage. But if a thirty tonne truck turns over on top of you on the bypass even the best racing harness ain't gonna save you.
