The telephone rang and after just a few seconds of listening to the person on the other end, my heart sank.

It was my father – who is 76 but still hopelessly obsessed by cars – wanting to know what I thought about the idea of him buying a 14-year-old Porsche Boxster S.

How on earth are you supposed to react to a question like that on a miserable morning in January?

In response I first reminded him of his age, and then went into some minor detail about how much a 14-year-old Boxster might cost to fix when, not if, it goes wrong.

But by that time he was already well into his stride, telling me how much of a bargain this particular example appeared to be, and about why he had already made up his mind he was going to buy it.