Happy New Year to all.
1) Auto-dimming is rendered somewhat useless with auto-leveling headlights as you've in many cars today w/ LED or HID headlamps; including the K900; unless there is a preference to switch to hi-beam when there is no on-coming traffic.
2) BMW 7-series don't always have auto-dimming feature, not on the E38.
3) I've found there is no one car that has all the tech do-dahs one would want unless you're into the current generation S-class, BMW 7s and the upcoming A8. Beyond auto-start/stop, blind-spot-warning, radar-cruise and panic-stop, cross-traffic-alert... which are becoming mass market, if you clamor for the latest in driver-less technology, self-parking, multi-function keyfob or cellphone app replacing the key, messaging seats, infra-red proj into HUD showing objects on the road beyond the headlamp range (or even laser headlamps which sadly the US DOT does not allow), auto-tilting of the car upwards on side impact (see the A8 features on youtube), etc etc; you'll have to swing around $100k for the aforementioned Benz/BMW/Audi.
Morals of story: tech is going 1000 miles an hour and the only way to catch up is to lease a top end Euro sedan every 2-3 years (preferably 2 than 3 ), or do as Steve Jobs once did, switch to a diff Merc every 6 mos (he did the SL)...