33125 Car Classifieds Site Ammending

Hi there, I have just opened up a UK based car classifieds website and the current web designer I am using for the website is unfortunatley, unable to make certain small ammendments on my website as it is beyond his knowledge. My website is [login to view URL], where users can advertise and sell their vehicles for just one pound (£) per month. Currently, new users that register with the site, (as you will see for yourself when you register) benefit from a free listing. I want to get rid of this feature compelltey as I am currently making no money from it and users will keep reguistering under different details in order to benefit from the free listing. I need somebody to get rid of this 'free' listing feature for me. Also, in the 'search field' on the website, I want it to be like that of the 'search fields' of www.autotrader.co.uk., e.g. Make, Model, Min Price, Max Price. Please can someone help me. Thanks