I recently discovered a slightly unpleasant truth relating not only to the Leon but to sub-100g/km cars in general.

I had to drive into the heart of London’s congestion charging zone for an overnight stay, and as my initial journey took place after the 6pm cut-off point, there was no need to shell out.

The following day, I hit the road in the afternoon when the charge was in force.

I took the Seat because its emissions of 99g/km were low enough to qualify for the outgoing Congestion Charge exemption, so I wouldn’t have to pay the tax.

London’s authorities recently lowered the exemption to vehicles emitting 75g/km or less, but said those beneath the previous 100g/km cut-off would enter a “sunset period” whereby they would enjoy exemption for another couple of years.

However, this caveat only applies to vehicles that have already been registered as exempt.

Never having driven the Leon in central London before, I logged on to TfL’s website to register for the sunset period exemption, forgetting that it was too late. I’d missed the boat, and ended up £10 lighter – one to bear in mind if you’re a fleet operating in London.