I sent an email to Toyota (toyota_cares@toyota.com) about an upgrade Nav option for non-Nav TCH. Below is their response. Maybe if more owners send emails they will act.

Thank you for contacting Toyota Motor Sales, U.S.A., Inc.
We apologize for your concerns related to the design of and lack of availability of a navigation system on your 2007 Camry Hybrid.

Currently, the navigation system for the 2007 Camry Hybrid is only available as a factory-installed option at the time of manufacturing. A dealership-installation kit is currently not available.

We make every effort to manufacture a quality product by researching, testing, and constantly monitoring performance. Consumer opinion and perception also play an active role in our ongoing efforts to lead the automobile industry in quality, innovation, styling, and reliability.

It is through communications such as yours that we become aware of the reactions and expectations of our customers.

Your email has been documented at our National Headquarters under file #200704130270. If we can be of further assistance, please feel free to contact us.

Toyota Customer Experience