I still think the biggest risk with a classic Mini is a heavy rear end shunt from a big car or a commercial vehicle. The ability of the rear end to sustain such an impact without the petrol tank rupturing plus the battery shorting out is doubtful should the impact mode cause this type of damage. Surely that is far more likely than a roll over crash.
In modern cars the petrol tank and filler are isolated from the interior. It's just he evolution of design for safety. I recall the Mk.1 Cortina GT I had where the boot floor was the top skin of the petrol tank!
The petrol tank problem is covered in this video taken from a TV documentary on car safety.
I believe later Mini's had a shorter filler neck to at least slightly improve the design.......
Edited by mab01uk, 19 August 2016 - 06:42 PM.