You’ve read all of your free items this month. To register, get added benefits and unlimited access to articles, Become a Member. Already a Member? Sign in. Advertising Age Article Abstract Automakers Buy Up to 80% of Ad Space on Car Sites for 2006 Moves Tighten Online Inventory and Boost Ad Rates By Jean Halliday, Published on December 29, 2005 0 Want more Access, Content & Connections? Upgrade to Membership. We are glad you are enjoying Advertising Age. To get uninterrupted access and additional benefits, become a member today. Register Now Already a member? Log in.