Many years ago I was driving with a colleague when I cursed a bad driver with a private plate. I said anyone with a personalised number was a complete knob. A while later I found out she had a private plate, one of those that nearly spells her name if you stand at an acute angle and squint a bit. But she’s a lovely lady, a good pal, and not a knob. I still work with her now and I’ve felt bad about what I said ever since. I was guilty in those days of holding very strong opinions on all subjects, regardless of evidence or knowledge (these days I’m quite happy to admit to having no view whatsoever on most topics). But I still have no desire to personalise my car with a private plate. I know lots of Mercedes drivers have them, so I was wondering, what’s the appeal?