EDIT: It's not a Mars orbit, its a solar orbit that puts it close to Mars at times.
From the linked article: "If all phases of the flight are successful - and that will not be known until at least 6.5 hours after lift-off - the Tesla and its passenger will be despatched into an elliptical orbit around the Sun that reaches out as far as the Planet Mars."
In 6.5 hours SpaceX will have finished everything they wanted to test with this flight I believe, including a number of post-launch checks of various systems and sensors on the payload, and those re-ignition tests of the 2nd stage.
It is in a parking orbit, where it will sit for a few hours and then will reignite and will be set on a trajectory toward "martian orbit".
IIRC currently they are testing (or proving depending on how confident they are) that they can have the second stage sit for several hours in space before reignighting.
>Upper stage restart nominal, apogee raised to 7000 km. Will spend 5 hours getting zapped in Van Allen belts & then attempt final burn for Mars.