You need to spend a bit of time writing a detailed advert, get the car all cleaned inside and out and then take some detailed pictures of the car. Here is an advert from my evo 8 mr which i sold last month to give you some ideas.

http://www.lancerregister.com/showthread.php?t=473298


The car basically sold itself due to the pics and advert. Otherwise if you write an advert looking like you 'cant be bothered' then people will get the same impression about the car.