The tax is established based on EPA gas mileage tests. The mpgs are determined when the cars go on sale, right? Ergo, the tax is determined, and charged at the point of sale.How could the 2016 GT350 have paid the Gas Guzzler Tax? The tax isn't even computed until after the model year run...much less paid. Has Ford said that their will be a GG Tax on these vehicles? Maybe to justify an outrageous price? Mmmm
If you look at the GT350 stickers, there is a $1300 GG tax applied because it gets shit mpgs.
I think you're confusing yourself by overthinking this.