Again, in the same vain as my request for information on aux audio, I would like to know how simple and affordable it would be to install the cruise control stalk? Where should I go for purchase and installation? NW London based.
If you've got a car with the loom already installed (pre facelift?) it's plug and play. You just need to either cut the hold in the steering wheel cowl, or replace it.
BMW were selling them on their eBay store recently for about £60 for the stalk only
Edit - just read your other post. I think you'll need the loom too. There may also be some coding required (if I remember correctly from a past post)
This thread should help:
http://www.z4-forum.com/forum/viewtopic.php?f=9&t=25063&hilit=cruise+retrofit
The M doesn't run an electronic throttle like the other cars so it's not plug and play I'm afraid. Still it should take less than half a day and is no more expensive than it was as a factory option.