What does your current nav DVD say on it? Is it HIGH or PROFESSIONAL? As I understand it, the Z4 has the same Nav setup as the X3 (ie, a Mk4 Navicomp, a flip-up widescreen and a CID in place of the usual Bordmonitor and Bm54 radio pack).

If it is a HIGH DVD, then you can load V29.1 (or anything from V27) to get perspective mode.

If you go into the Nav setup page, what is the version info at the top of the screen?