i'm an old fart, and have forgotten most of what little i ever knew about this, but for me, the most infuriating thing is that our cars (not my car, it's >7 yrs old) will now have routeable IP addresses.
and no one remembers the occasional story of a child with a tablet hacking daddy's jeep, or whatever.

. . perhaps IPv7 will just be IPv4 with 48-bit addresses.

yeah i know, never happen