Hey guys. I'm planning on building a site similar to carsales.com.au.

I have a business Idea that needs a site with the same kind of function. People need to be able to join, make accounts and post adds etc as well as have different types of accounts with different privileges ie; private, retail, wholesale etc.

I'm told to build something like this I'm best off starting from scratch but I dont slightest idea on how to do that. I've only had a couple of wordpress based sites in the past and from what i can see wordpress isn't really a good way to go for the application.

Can anyone tell me what would be the best content management system to use?