It means it wasn't as much of a financial success (from a business standpoint) as its founders hoped, and they have departed for greener pastures.
Carsabi is/was a great site, and well designed and well coded, but its revenue model was lacking.
Is there any potential sustainable business in the area Carsabi tried to tackle? I personally feel lots of pain points there but I guess it might be too hard for Carsabi to solve alone? Relatively, it might be easier or more tangible by just joining Facebook and get a quick good exit.
I'm interested in buying carsabi as well as teaming up with developers. It needs a different model to make money and I know of a great one which I already developed. Contact me if you want to tackle the used car market.
I know someone who may be interested in purchasing the IP assuming it is for sale. Email me in my profile if you guys want his name and contact info.