It's not a registry per se.
The CRG database has 17,000+ vehicles in it with data gathered from many different sources - cars, documentation, orphaned engine/trans, forum posts, data submitted, ebay, etc.
It was designed from the beginning as a research tool - gotta have data if you are going to have facts to base research on. There are no plans to ever make it publicly searchable/available. The confidentiality of the db is a key feature that has resulted in data being submitted that otherwise would not be available. The data results from the db appear throughout the website - paint percentages, research articles, etc. It can also provide history on a car - not it's original intent, but ask Marty how it helped him trace back his car.
You can email 67 data to Daniel - email@example.com