In the Top Gear Botswana Special (series 10, episode 4), the credits look like this:
Presented by
Archbishop Desmond Clarkson
Archbishop Desmond Hammond
Archbishop Desmond May
and
Archbishop Desmond StigFilm Camera
Archbishop Desmond Harvey
Archbishop Desmond May
Archbishop Desmond Leaver
Archbishop Desmond Kennedy
Etcetera, etcetera. Everybody's name has turned into Archbischop Desmond name.
What's the story behind it?
It's probably a reference to activist, Nobel Prize winner and Archbishop Desmond Tutu. But while that man has achieved a great deal, he wasn't from Botswana. He studied at a university named after Botswana (but based in Lesotho AFAIK, not in Botswana itself), so I don't see a direct link.
Top Gear's wikia doesn't have an entry on it.