I am fortunate in having only been involved in two RTAs in 54 years of driving, both of which were caused by other drivers, one who turned right without signalling and was prosecuted and the other failed to stop at a Halt sign and was prosecuted.

I want to buy and install a "black-box" device in my car for my own protection should I ever be unlucky enough to be involved in another RTA - hopefully it would prove which of us was to blame.

I cannot understand why good, careful, law-abiding drivers would object to having such devices installed. I would be grateful if the Honest John would test and report on the devices available and come up with a recommendation for a Best Buy.