Dear Terry,
My girlfriend drives a 2005 Jeep Wrangler that eats gas like no other -- she gets 14 miles per gallon in the city and 18 mpg on the highway. She currently owes $20,000 with a 16 percent annual percentage rate and now wants to sell her vehicle or trade it in for a Toyota Prius.

She has $2,000 for a down payment, but in the end she will still be in an upside-down situation. Do you have any creative ideas on acquiring a new Prius that is gas-efficient with this scenario?
-- Tomas

Dear Tomas,
This is a tough situation because the Wrangler is probably worth at least $6,000 less than what your girlfriend owes. On top of that, dealers are getting top dollar for a Prius, so she can't expect any deals.

If she rolls over the negative equity into the Prius, even with $2,000 down, she'll likely end up with a loan of $25,000 or more, since even the cheapest Prius lists for more than $21,000.

Save some more money, drive the Wrangler for a while longer and then reconsider.

Here are this week's reader questions:

• Mileage claims fall apart in real world • Which option is best for a short-term auto? • Do lenders get financing kickbacks? • Any creative ideas for ditching my gas hog?

If you have a question for Terry, e-mail him at Driving for Dollars. Save money on your car -- sign up for Bankrate's new weekend Car & Money newsletter.