I've experienced it once in a trans-Africa truck trip but can't remember where.
I think in many areas, like West Africa where there were numerous ex-British and ex-French colonies, they've all actually swapped-over to the same side to avoid the issue.
Except for Zaire/DRC, most of Mid and Southern Africa used to be pink on the map so they drive on the left, including - interestingly - Mozambique, despite it having been a Portugese colony, so there's no issue crossing there to/from South Africa or Zimbabwe.
But doesn't Hong Kong still drive on the left, whereas China 'proper' (the PRC) drive on the wrong side ?