Get a corolla/civic/focus...etc...They should get you pretty good gas-mileage and they're very reliable cars. You can fetch a decent mileage one for around 7k and that's not too old (maybe 1999 or something).
Here's the best buy of 2003:
http://auto.consumerguide.com/auto/n...tingtype/1.htm
Maybe you can find an older model of these cars that's around $7k.