They weren't free. They were subsidized and consequently what used to be a $20 converter jumped to $35 overnight because that was how much retailers knew they could milk out of the rebate.

Adapters are not much use on a car, are they?

They are available https://www.autoexpress.co.uk/product-group-tests/88304/best...

Just a matter of time before my state makes it illegal to touch one of those while driving, if they haven't already.