I hunted nilgai on a place just south of the King a few years ago. Money Game is right - a gas powered (quieter) F350 with two rows of seats in the bed. Once you see 'em, hold on. Driver hauls ass until you get in range, then he slams the breaks. Shoot until they all stop or are out of range. Mind you, this was after deer season was over and I was invited down as an alternative to them opening up the place for day hunters. Their biologists determined the guys on the lease hadn't taken enough off that year for both the nilgai and the cattle to have enough grazing room.
I've been told a more traditional way to hunt them was to find a pile of dung, sit back, and wait. They always squat in the same place.