I’d taken delivery of a sparkling new Mercedes A45 AMG just three days earlier, and until then I’d been revelling in the joys of new car ownership.

Working out what all the buttons do, enjoying the smell that a new car gives off and bonding with the thing generally.

And then, crunch, turning right out of a side road I could feel that I’d run over something weird; something that was so small I didn’t see it coming, but which was also sharp enough to make the front right tyre sound like I’d just inserted a massive blakey into it, hence the tell-tale 'tic, tic, tic' I could hear from then on.

So I pulled over, wound on full left lock and rolled the A45 gently forwards in neutral, and sure enough there it was, a great big screw head staring back at me. “Oh bugger,” I thought, and as Paul Whitehouse might say. And then I headed straight to the nearest Kwik Fit, which just so happened to be not very far up the road at all.

The screw was a pretty big one, but I’ve never yet known a puncture like this to be un-fixable. As long as it’s in the treads they can usually insert a small plug into the hole and then seal it with adhesive. 

The Kwik Fit man agreed that it was indeed a big one, but he also agreed that it could almost certainly be fixed. So he whipped the tyre off its rim – and promptly discovered a tiny but deep slash on the inside shoulder of the A45’s otherwise brand new 235/40 ZR 18 Continental. Unfortunately this had ruptured the tyre’s core, which meant that it couldn't be fixed.