Bloomberg opinion: heavy US car sales on Black Friday and today's cheaper gas don't mean overall big car sales are poised to increase.
If there is a big boom in less efficient vehicle purchases right now while fuel is cheap it puts the car companies in the position of having to increase efficient car sales in order to meet CAFE standards.
They would end up raising the prices of the least efficient models in order to slow sales and drop the prices of their best MPG models, EVs and PHEVs.
This has happened before. Demand for inefficient vehicles was high so manufacturers charged a lot more for them and sold their most efficient for very sweet prices. Some have claimed that they were losing money on efficient vehicle sales and making it up on inefficient vehicle sales.
Of course the nice thing now is that since PBO negotiated new CAFE standards they also apply to light trucks/SUVs. Before those sales weren't controlled by mileage standards.
Summary: at worst a temporary blip to be evened out during the rest of the model year. Perhaps by discounting EVs and PHEVs where the most gain is found.