I guess you guys don't remember/might not be aware of... But they've actually done night safaris at DAK (Years ago.) Even funnier, they were pretty much exactly what someone suggested:
-reduced number of trucks
-Spotlights mounted on the trucks
-2 cast members... one drove, the other speiled and used the spotlight to highlight things.
From what I hear the animal show was terrible... basically no real animals to be seen. To compensate, it was an entirely different script including a tribal wedding (actors in the first elephant yard dancing around a fire) and some interaction with Ms. Jobson (an actress standing by a jeep "looking for lions" near the Kopjes area where you often spot the lions.) The Poachers scene was also a bit different (same overall theme but slightly different storyline, and if I'm not mistaken, again a few more actors involved.)
It definitely sounds interesting, I wish I could have ridden one when they did them. (It was a very short/limited test one Christmas season shortly after the park opened I believe...)