I would highly recomend whatcar.ie. After having my car on carbuyers guide and autotrader for months, it sold on whatcar in no time. I guess everyone knows about the AT and CBG but only genuine buyers would have known about WC back then. And yes, they won an internet award last year!
DO put very good quality photos of your car on the add - use a digital camera as opposed to camera phone. show all sides and inside of the car
DO look at cars similar to yours for pricing your own - people always tend to over value their cars - if you want to sell yours quickly then price it accordingly but remember the market is flooded with 2nd hand cars and it is not easy to shift your car so really put some thought into pricing your car.
Does anyone know which website suit which type of carfor sale. Like where would the best place be to put a high end car like a 06 BMW 3 series versus a low end car like a 00 Fiat Punto. Is any info available on this or what is the experience of the people on here?