Handsome devil huh?
The cards from this expansion have the same design as 51st State: are they as good an addition to The New Era? how much do they add to The New Era? I could not find many comments on this in the ratings.
The cards are basically a promo pack expansion for 51st State, regardless of being marketed as for The New Era. All the cards, except for the Leader Card (Mike Highway) can of course be integrated into a game of The New Era though (and even Winter), just as all the original 51st State cards can be used in The New Era. The only thing they lack is the Defense Distance symbol.
I should perhaps also note that while the Car Patrol has a really cool use in the game, the iconography used isn't perhaps the best. Reading it according to its icons it seems you have to Discard an Open Production Card in order to Gain a Closed Production card, but it's rather simple to remember that sending workers to the Car Patrol allows you to change an Open Production Card to a Closed Production Card for the rest of the turn.