Actually I found this online:
From the "Glossary of International Shipping Terms"
Line Release System - The Line Release System, a part of Customs' Automated Commercial System, is designed for the release and tracking of shipments through the use of personal computers and bar code technology. To qualify for line release, a commodity must have a history of invoice accuracy, and be selected by local Customs districts on the basis of high volume. To release the merchandise, Customs reads the bar code into a personal computer, verifies that the bar code matches the invoice data, and enters the quantity. The cargo release is transmitted to the Automated Commercial System, which establishes an entry and the requirement for an entry summary, and provides the Automated Broker Interface system participants with release information.
Not quite sure what that all means but it may be something that helps the flow of paperwork through Customs.
So I think that the cars may still be in Customs, but who knows its been at the port for 4 days already.