Automotive Website Vendors today are more intelligent than ever and are going to continue to get better. Nothing you can do on your own including hiring a Full Service Online Marketing firm could build you something as integrated. Believe me, we work with them all the time. And...I used to be one.
Terrence, I disagree. Website vendors today provide virtually the same thing across all dealer websites. I can tell which website vendor did which website based on the homepage design or their vehicle details page (without seeing the site credit). It's a shared system. The only thing that's actually "custom" is the homepage design. Inventory, rebates, lead forms, are all shared parts of the system. Sure, they can re-skin it -- but some dealers would rather control the whole experience.
I do agree with you that it is a challenge to integrate with the vendors who specialize in inventory, rebates, credit apps, etc. and that the last person you want designing a custom site like this is a full service marketing agency!
What I believe Clay had in mind was utilizing a modern, mature CMS and hiring a developer to build custom parts of the site (modules) to handle things like inventory. I assume, and correct me if I'm wrong, that he is frustrated with the seemingly cookie cutter
functionality among him and his competitors websites. He's outgrown the functionality and wants to do some more custom things, that I'm afraid
most website providers won't offer. It's not profitable for dealer website vendors to do one-offs.
I just wanted to offer my advice and let Clay know that it is in fact very possible, and that finding a developer with a great deal of experience in these CMS's can deliver. It's also something I encourage as like I said before, it's not difficult to tell which vendor did which site. I'd love to see some unique features and interfaces. I also think it would be incredibly effective for his dealership if done well!