Any car. Many miles. Go on, choose.

[Ferrer]

Exactly. If these are straight roads, that is, and I ain't paying for gas. ...and it has to be a convertible.
If hilly twisty mountain roads, a Lotus Elan. 3,000 miles might be hard, though. I'd go through so many Lucas Electric's products, it'd be more expensive than gas for the Continental.
If a mix of the two, E46 M3 or E90 335i.

Elan would be excellent in the Top Gear road trip to find the greatest driving road that they made a couple of seasons or so ago. But if you had to combine twisty mountain roads with city driving then the Abarth 500 SS.