People defending the system: are you presupposing it is perfect? Because let me tell you: - Start-stop when it first came out was not perfect, still isn't * - Automatic headlights were and still are pretty abysmal - Crash detection systems are horrendously bad - My car thinks it knows the speed limits of the road I'm on but it's often wrong I'd love to know what new modern cars you drive with perfect 'safety' systems…
I've had these in three cars, they're not too bad; other than the ones without an easy way to turn them off are terrible for ferries and drive-in movies. Automatic high-beams are pretty terrible though, but IMHO, you should rarely have your high beams on if you're within 2 miles of another car.
> I still find that start-stop incredibly annoying on automatic cars
I've rented a variety of cars with different systems. Some of them are truly awful, but the ones that sense when you start to pull your foot off the brake, and have a short start time aren't awful. Probably I'm not buying anything with start-stop; my last new vehicle was half a model year before they added it, and my next new vehicle is going to be a hybrid, and I if I buy more old vehicles, they're likely to predate start-stop, probably by a significant amount.
I will also add that existing cars that report the speed limit to me are often wrong in both directions, so I wouldn't trust anything other than a very mild warning. You want to show the speed limit in black when I'm under it, and red when I'm above it (preferably by at least 3-5 mph), go for it... that sounds nice and useful. You want to beep at me once gently if I go 10 mph over and maybe once more at 15-25 over? Reasonable, I suppose; maybe even a reminder beep every 5 minutes. Anything more and your data had better be completely accurate.