https://peloton-tech.com - I mean, that's just one company, I think there are a handful working on just the problem you're talking about.
[1] I assume also some regulatory developments for this are missing in addition to platform and universal tech kit for private cars. In case such platform already exists and all regulatory hurdles have been tackled, then I miss only widespread adoption and marketing...
I mean, you could do a retrofit kit for regular cars, too... but that seems harder to get exactly right (I mean, considering the cost of a fuckup) and would require a bunch of new marketing infrastructure, whereas if Ford, say, just bought peloton and said "hey, make this work across our model lines" - well, that'd be a pretty good argument for buying a ford.