This is a wild tale of the EPA trying to “update” official federal miles per gallon ratings — and probably blowing up untold Cash for Clunker subsidy deals in the process.

Seemed every car dealer in Charlotte was trying to cash in on the federally-backed trade-in program last week. But eligibility hinges on the EPA ratings of the vehicles involved, and that is precisely what the feds just changed.

Upshot, go back and double-check the numbers against the new, new EPA ratings to see if any deal you made or want to make will get the Uncle Sam handout. You are going to hear so much more about this in the coming weeks.