But first... just a little more sleep. Sorry if I'm shattering your notions of Lion behaviour. They do earn their prodigious rest with amazing displays of predatory prowess and general carnivorous intensity. It's just that seeing those moments takes tremendous luck and once-in-a-lifetime timing. Most of the time they lay prone, breathing heavily, waiting out the heat, and biding their time.
Don't think you should get out of the car though. It would be the equivalent of a warm blueberry muffin magically appearing next to you first thing in the morning... it wouldn't stand a chance. The lions ignore the cars, basically treating them like big moving rocks, but a person hopping out of one would likely cause some excitement.
In the video below, you see that they often get up just to find a better place to get back down.
[vimeo http://www.vimeo.com/35615892 w=590&h=332]