Look, do yourself a favor and buy a decent mini s with anywhere from 10,000 to 20,000 miles on it. I have one, get the manual... automatics are for girls and men who wear panties. It is fast, fun, reliable and I average over 30 mpg overall.
Buy a golf gti, another great car. The dsg gearbox is fantastic, again great reliability and gas mileage.
A few years old mazdaspeed 6, not many made, but those that were were awesome cars. They can be had for a decent amount of money. Not the best gas mileage, but a mechanic can take the limitor off and you can easily pull 170 on the highway. Great handling, although it is not a gokart like the other two cars I mentioned.