We never cease to be amazed at the audacity and callousness of some criminals.

Grandfather Eric Truby thought he was doing his son a favour by helping to sell his £4,600 Toyota Landcruiser 4x4.

But when he took a couple, who called at his door, for a test drive, they left him abandoned in the countryside at Islip - in his slippers.

With no mobile phone and no money, he had to hitch a lift several miles to his home at Yarnton.

Thankfully, despite a heart condition, Mr Truby appears to have suffered no ill-effects from his ordeal - apart from perhaps wounded pride.

But the incident should serve as a warning to anyone selling a car.

Motoring organisations say that criminals are being increasingly frustrated by more sophisticated car security systems, which make breaking in more difficult.

So they are thinking up new ways to get what they want.

Conning an owner, or in this case, the owner's father, into giving them a test drive, then dumping him at the roadside appears to be one of them.

Given the popularity of 4x4s, one would assume that there is a profitable black market for such models.

The motto would seem to be don't trust anyone, however plausible they might seem.