There is no need to run one on red diesel, with the multifuel engine they can run on contaminated (water/diesel mix) from recovery companies. We have owned 2 FV432s, one of them I registered for the road and did drive it on the road. I did not enjoy the experience, the width is an issue as is the drivers hatch sticking up in the air preventing you from seeing to the left. The thing I dislike most is that you have to steer and stop with the same levers. Pull them both back to stop. If they are not correctly adjusted, or you pull one back further than the other it will not stop straight. They are great fun off road though, and with free fuel you can play all day, or untill the tracks fall off.
If you want something a bit more road friendly then a CVR(T) is the way to go. They are more expensive, but with good reason. Compared to an FV432 they are tiny, but vision, manouverabilty and handling is far better than a FV432.
Chris