CONEY ISLAND - The Metropolitan Transit Authority (MTA) is testing new automated subway cars on Brooklyn?s N and Q lines. The 30-day test is designed to work out any kinks in the cars. The MTA has already spent $900 million to upgrade its fleet. If the test is successful, the entire system will be upgraded by 2008. The MTA has not decided which lines will get the new cars when they enter full service, but say they will be more reliable and easier to repair.