Complex sentence: Contrary to common belief, this was not a South African vehicle but rather developed in the US without South African involvement, though based on an evolution of vehicle mine-protection technology used by the UK, Rhodesian and South African forces from the 1950s onwards.
Split into simpler sentences: Contrary to common belief, this was not a South African vehicle but rather developed in the US without South African involvement. That said, it was an evolution of vehicle mine-protection technology used by the UK, Rhodesian and South African forces from the 1950s onwards.