Curious as to why you're buying new? Is the used parts market not all that big over there?I hit post before I finished that. My thought was that since none of the units are really compatible with my car I would save the $500-ish and buy the -D suffix'ed part number. I don't know why it's cheaper than the rest but this will be the second MIB 2.5 I've bought so savings are welcomed.
Here, you can pick up a used main unit for like £400 ($550 ish)!