How modern are you talking? I've seen some very new cars (I think in a trip to California once, driving an SUV thing that almost needed two lanes to itself) with slightly odd mirrors - perhaps slightly concave or convex? I don't remember, but it had more view, and I vaguely remember the 'image' being distorted slightly though?
Besides that, no car I've driven has had that feature, and I've owned cars from VW, Honda and Toyota all built from 2005 onwards.
In what situation were you travelling forward close enough to rear-end another car that you also needed to check your blind spot?
Hit the right light of the car in front with my left one. Now causing real slow down and even more traffic jam.
There are cars with 3 mirrors that don't have blind spots, without having some other tradeoff instead?
That makes the blind spot radar/lidar/camera systems on new high-tech cars seem pretty dumb!
Difference is radar/lidar both emit the radiation they use to see themselves. It's hard to illuminate a car's outside completely from within the car.