Auto Script for Classifiieds, Wrecking Parts + WANTED

We need a new website from an EXISTING SCRIPT that allows us to use classifieds, Selling Auto Parts as well as HAVING A WANTED section that sends an email immediately to every registered member wanting and / or selling a new / different auto part!!! The website also needs to be integrated to a CAR RENTAL SCRIPT that we need as a major part of our website... WE NEED AN EXISTING SCRIPT TO CUSTOMISE UNLESS YOU HAVE DESIGNED A SIMILAR SCRIPT previously.