Yikes I did the same thing with Coke about 10 years ago on an almost new car. It was sitting in the front seat while I was golfing and 5 hours later: kaboom. All over the seats, headliner, dash and vents. I scrubbed the crap out of my seats with carpet shampoo but the headliner was a ***** to get out but you still could see a faint stain. The vents were the worst as dust would stick to them and the way they were designed you really couldn't get it all out.
Any dash cleaner would work. For the headliner there's this stuff called spot shot carpet cleaner that takes out cola. Try it on a small area so it doesn't change color. You should be able to get it at Walmart.