I personally feel like pricing in tax refunds into the displayed cost of the car is fair game, but pricing in gas savings is bullshit.

Tax refunds is money I'm definitely going to get back in a bounded (and reasonably short) amount of time. If I pay $40k for a car and get $7k back in the same year, it seems reasonable to advertise the cost as $33k (assuming it's clear that $7k of that is a tax refund).

But gas savings feels like bullshit -- it's money I may or may not get back (depending on my habits), the time horizon is unbounded, and even if it were bounded, it's long (an order of multiple years). That feels deceptive to me, and it's surprising they got away with it until now.