Every now and then, one of the classic car magazines runs a type of story that has always baffled me. It begins with the revelation that something like a rare Lambo has been found abandoned in a garage.

Reading on, we discover that it's been there since 1980. It's very dusty and the tyres are flat but, remarkably, it's complete and in need of only 'gentle recommissioning', as the classics lot put it.

A few months later we see a picture of the same car bowling down a tree-lined road in the hands of a bloke who never imagined he could get his aforementioned hands on such a thing. Marvellous.

Now here's what I've never understood. How did anyone ever forget about owning a Lamborghini? Or grow bored of owning one? How did a car that is obviously in sound condition end up sitting idle for 25 years? If the previous owner didn't like it, why wasn't it sold? Or even given away? All it took was a postcard in the local newsagent's window.

I can see how a fountain pen might work its way to the back of a desk drawer and be overlooked for two decades. A few years ago I bought my girlfriend a pair of boots that she didn't really like, and they are in the corner of her wardrobe, still in the original box and awaiting the great day when they appear on eBay as an item of mint and unused retro chic.

But a car? I really don't foresee a day when I can't be bothered with my Boxster any more and I just leave it in its garage gathering mould and mouse droppings. Apart from anything else, I'd want the storage space.

But now I understand exactly how it happens. For the past month I've been driving around France making a new programme for the BBC, and for this purpose I bought a 1989 Jaguar XJ-S convertible.

It was a good one. Everything on it worked, there was no rot, the hood was free of tears, the mileage was confirmed at under 60,000, and I loved it. Before I left I had it thoroughly serviced and checked, and a few marginal components such as radiator hoses and brake pads were replaced.

It still had its original toolkit and spare wheel, and even the unused bag thing that the conscientious owner is supposed to use to cover the hood when it's folded. And I've always wanted an XJ-S convertible.

After a few days of driving around France, it sprang a small oil leak. Tiny, really, and from the little micro switch that governs the oil pressure gauge on the instrument panel.