It does its job.
2011 Ford Focus
I'm not really sure what it does for the onboard BCM but it works fine. As another review mentioned the original separate Dash Top display now only displays DVD in the upper left and the Temp readout still works on the top right. This is on a 2011 Ford Focus. The kit was easy to install (I'm experienced). I had it mounted to the new replacement center-stack panel and wired up before I ever removed the factory radio. That done it only took about an hour to replace the factory radio and run wiring for a pair of subwoofers. Since my car did not have steering wheel controls, factory subwoofer or sync & sound I'm not sure why I really needed this. But my knowledge of modern car systems lead me to trust Crutchfield that I need it. Axxess makes an interface but it isn't offered here. The steeply discounted installation kit and service makes it worth buying what Crutchfield offers. Other sites were more expensive overall when installation gear was added in though I could find the radio itself cheaper.
Pros: It does it's job and I have no fault codes.
Cons: I wish it somehow would keep the clock working in the original factory display on top the dash. Original factory display shows DVD in the upper left. There has never been a DVD system in this car.