[levocardia]

Cash for Clunkers was not mandatory

[ARandomerDude]

Not being mandatory and not having an effect are different claims.

[frollogaston]

Wasn't mandatory to sell your car. Was mandatory to pay taxes that were partially used on those buyouts. You also couldn't opt out of used car prices being higher because of it.

[Exoristos]

If you keep a population poor enough, almost anything can be functionally mandatory.