I just ordered the latest version Nav software from the link below. The seller has a good description of the different versions of software, and clarifes that V29.1 is the latest for the MKIV, and V30 only has updates for the E65 and E66 series. By ordering V30, I am in fact getting V29.1. I was going to download and update from the link on X-5 world, but I tried that a couple of years ago, and ended up crashing her MKIV unit. The dealer replaced it under warranty, and it had V26 which was the latest at the time, but i decided to spend $15 and get a professionally burned version. If the link doesn't work, go to eBay and search for "nav V30"
It's the little things in life that I look forward to!