So you have multiple websites and you want to share content and users across multiple domains? But wait you want it to be simple and managed from one domain? Well you could use multisite, but that can be tedious and cause lots of issues especially with a huge amount of sites and databases required, different content types, client changing their mind non-stop, new funcitonality arising at each step. Once again Toyota UK dealer websites required this and the previous methodology behind it was to use multisite and XMLRPC, but this wasnt successful and required a lot of custom module development. I'll explain the pros and cons of multisite and domain access, why domain access was used, the cool integration with views and content types and basic permissions of domain access.