One of my number plate lights has blown. The owner's manual gives naff all about a replacement but an internet search throws up the complete unit; lens and bulb integrated as the replacement item. Can't only the bulb be replaced?

Yes they can, just undo the two screws, and pull the unit out. 

Not sure why Skoda decided to stop detailing the bulb types in their manuals.

 

It's almost certainly a 5W festoon bulb...

 

 

Thank you. On Euro Parts website they only show the complete assembly for £10. I will take it apart tomorrow

Done it. Don't suppose the Lucas bulb will last 5 years

Well, they do say "Lucas, the prince of darkness".