Get a low mileage extended warranty 1999-2001 used Mustang GT.
The GT is more than just an engine. It's an engine, tranny, power options, rear end, handling package, traction control, and brake upgrade. The GT will hold it's resale far better than the V-6, will probably match the fuel economy, and it will be much nicer.
That is of course if you are being supplied with 18k. If you are just being promised a new V-6, and nothing if you go the route of a GT, then get the V-6.
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