The E85/E86 Z4 has the MKIV nav. It uses the 'High' version of the maps.
I keep looking online but it's really hard to even find the official maps for purchase. Plenty of places are selling copies of the discs, but I'm not about to pay someone else for a copy, I'd rather make my own, but I can never find what I need to do that.
edit: finally found the official source
http://store.bmwgpsmaps.com