Things were going well: the Five was behaving itself, starting on the button and driving superbly for a 21-year-old. Until that is, I left it unattended for a couple of days. When I picked it up originally, the previous owner had needed to jump start it using his wife's car. This should have sounded the alarm bells, but it was cold and wet and I wanted to go home.

So in I came one morning last week to find that the driver's door would only unlock on the key. Of course, a quarter turn of the ignition revealed the battery was completely dead. No matter, I thought, I'll just jump it back to life.

Shortly after, it was back with us, and after a further 20 minutes at idle I got behind the wheel to run it up and down the road a few times and get some charge in the battery. However, a quick test of the headlights killed the engine instantly, and although it would turn over and fire by itself, the request for extra power for the lights resulted in the same thing.

I'd been assured by the previous owner that the Five had been treated to a new battery just two months back, but what greeted me as I lifted up the rear seat bench to access it reduced me to swearing and the foetal position. 

A previous battery had clearly given up the ghost and spewed its discharge into the floor plan. Said acidic discharge had then eaten away at the paint and soundproofing, leaving behind what looked like a lethal tiramisu with a car battery sat on top.