As @tourdeforce said, if that's all they can stop you for you're doing well.

However, I've been stopped, twice, in about 10 years of overland travel because I didn't have a "GB" sticker on my 110. I paid about a GBP10 fine for one of the incidents, the other one waved me on when I STARTED SPEAKING ENGLISH LIKE A TOURIST :)

So, small chance of a small fine or just don't bother and worry about making camp to catch another glorious african sunset!

Alternatively, you could do what we did with our Landcruiser. We too were worried about the reaction we would get in some places thanks to Bush and Bliar's dog's breakfast in Iraqistan, so we had some German-style plates made up by Show Plates Quality Acrylic and Metal Number Plate Makers. The Landcruiser reg no was H84 FRV anyway, so it could almost pass for Hannover. We hoped that if anything ever happened then we could simply point to the number plates and say we were German.

Funnily enough, nobody ever seemed to care particularly where the Cruiser came from and our nationality was never an issue. The plates did earn their keep in other ways, for they got us into a few conversations with Germans/Swiss who thought we really WERE German!

overlandcruiser.net