SugarCRM is great, but you need someone to install/configure it for you. Out of the box there is way too much going on and, as Mike said, it will take a long time to understand how it works. That said, if you end up with a sales team one day, it's a phenomenal tool for teams and reporting, etc. If you just want to track contacts, use Highrise or something similar.
There are generic Wordpress templates, like those that Mike suggested, but none of those are going to come with any automotive specific styles, which would require you to have a fair bit of custom work done to add in vehicle details and listing pages. I still think it's worth it, but depending on what that's going to cost you, it might be excessive if you don't intend to stick with Wordpress long term.
I can't speak to the actual quality of these, but I know someone using:
WordPress - Light House - Clean Real Estate WordPress Theme | ThemeForest
ThemeForest has a few "Automotive ready" site templates and Wordpress themes.
Automotive | ThemeForest
I would recommend first making a list of what you want your website to do, then Mike or I can probably recommend the best plugins to achieve that, then find a theme that is flexible enough to allow you to do what you want.
For what it's worth, I prefer custom Wordpress themes and if I'm stuck in a Wordpress project I won't do anything but custom anymore.
