Nothing has been finalized so unfortunately you'll have to wait for the details. I think the main points of debate based on what I've read so far are:
- Would it apply to all cars manufactured in the US or just Detroit. (I doubt they can limit it to American cars)
- What's the minimum mpg that the new car should achieve (current regulations or future regulation).
- Instead of a minimum maybe it should be based on an x% improvement over the outgoing car.

Until they iron out all the details it will be tough to speculate. Unless you are in a hurry waiting a few months might be the right thing to do right now.

 

I heard about this the other day and that they were still debating on it. I'll have to do some research on it. Since I'm turning in a lease I thought about going out and buying a clunker to turn in when I buy my TL. But a POS for $500 and trade it in and still net $4000.