If we must go down the road of trying to legislate away stupidity can we at least do it thoughtfully? I would imagine we could accomplish the same thing by requiring baby car seat manufacturers to put a sensor in the seat belt of the seat combined with a keychain dongle that is notified everytime the belt is buckled/unbuckled. If the dongle gets taken far enough to lose contact with the seat while the belt is still buckled it starts screaming "DON'T BE A BABY BAKER!!!" Or at least beeps annoyingly.
Far less kids are born each year than new cars sold making the effort less expensive and better targeted, not to mention that people who don't have small children are not saddled with additional cost.