As KIPAX mentioned the only time you need your windows shut is in with the Lions (don't remember seeing any tigers or other big cats even though they're listed on the website) and the baboons. Got a couple of funny shots of the baboons on the ex girlfriends car though!
We went mid week so it was pretty quiet, and although it was a bit of an over cast day I got some really nice shots. Probably my best shots are of the meer kats, always one on the branch stood up taking watch.
Obviously you'll need a telephoto lens of sort some for the safari shots, I had a 70-210mm, but at times wished I had a 300mm or more.
Cheers,