Hi,
one hour ago I upgraded my X5 A00 to A04. I found two step upgrade, follow these links below:
Upgrade A00 -> A02
Upgrade A02 -> A04
Mybe it is possibe in one step, but I didn't found it ..
Then I was trying to upgrade A04 -> A05 with R64365 file, but without success.. I'm trying to solve this problem now.
Good luck! jan