A few other pieces of advice:
Less is more in your craigslist ad - list the essential information needed for making a decision about the car - year, make, model, transmission, title (clean vs. salvage), mileage. You could consider adding info about any recent upgrades repairs (e.g., new tires, replaced X last year), but that's not necessary. Ads that have a whole story about the car and a million details tend to be distracting or make me worry something is hidden in all that text!
Clean the car and take nice photos of it. A sure-fire way to not sell a good car is to post the listing without pictures or post blurry pictures of your car covered in the kids' cheerios and toys.
Respond promptly to offers. When I'm buying on craigslist I may be sending out texts / emails to 3 or 4 different sellers. I've had sellers respond days later and by then I've often already bought something from another seller.