This is a how-to for anyone interested in adding cruise control to their second generation 2008-2011 Focus.
Before you begin, consider this: you will be removing and reinstalling the steering wheel and air bags. There is high potential for serious injury or death, so do not try this unless you are completely comfortable working with these items.
The dealer can get you a new steering wheel with cruise control buttons for around $300. However, if you are patient and look carefully, you might be able to find a deal on a used part through the various part sources. I was able to pick up a used steering wheel with cruise control buttons for under $100 shipped to my door.
Remember that you are monkeying around with the air bag. So disconnect the battery and make sure the system is completely discharged.
Here is the boring old factory wheel without cruise.
If you look up under the steering wheel, you can see where you have access to remove the air bag. Drop the tilt steering wheel lever down and you can get a screw driver to each of the 3 tabs that hold the air bag in place:
Here are the tabs that you are moving as seen from the new wheel:
This is what you want to accomplish. Here you can see how the tab holds the air bag in place:
And by moving the screw driver you can see how it releases:
Now that you have the idea, climb under the wheel and remove the tabs. They really go easy:
Once you have popped the tabs, the air bag can be removed:
Carefully disconnect all of the electrical connections and remove the airbag completely.
Some folks have reported that they were able to remove the steering wheel without a steering wheel puller. I wasn't. In fact, I had a hell of a time getting it off even with a puller. Just to test, I tightened the new wheel down and then removed the bolt again to see if the new wheel would pull off: nope. It was on there. The bolt is a 24mm in the center if I remember correctly. You can rent a steering wheel puller from many local part stores: the local O'Reilly's charges a $50 deposit, but it is refunded 100% if you return the tool within 48 hours.
Once you pop the wheel loose it comes right off
Comparing the new wheel to the old
Here is the difference between the two wiring harnesses. The one without cruise is missing several wires, but the plugs are identical. This is part of the reason this swap is so easy. Everything is there, just need the buttons!
New wheel goes on, and tighten down the center bolt.
Reconnect ALL the wires. Don't miss any or you will end up with an air bag light on. :)
The air bag pops right back into place. Because the tabs are spring loaded, you don't have to move them back into place. The air bag is back and the car is ready to go!
Reconnect the battery and put all of your settings back. I usually pull both battery cables off the battery when working on things like this. I connect the positive cable back first, then the negative.
Then it is down to the dealer to have them connect the IDS to the BCM and turn the cruise from "off" to "on."
Probably a 15 minute job unless you take your time and snap a few pictures. :) Let me know if you have any questions.