The active cruise control works fine at keeping your distance at higher speeds, but the active steering only works on motorways & dual carriageways, and at speeds up to (I think) 25mph. I've tried it a couple of times, but don't use my car much on those kinds of roads. It's weird, you have to keep your hand on the wheel or it switches off, but then it tries to pull it out of your hands to keep within the white lines.
Duncan, I don't know 100% as my car has driving assistant, but are you sure there's active cruise control on standard cars? I hope you're not relying on what I think is a typo on page 50 in the printed brochure - I'm pretty sure that's wrong.