It's not that vehicles aren't be shown in the garage, it's that they're not being inserted to the database.
[22:59:52:050037 --4:00] [Thread 4364] extDB2: SQL_RAW_V2: Error StatementException: SQL: INSERT INTO vehicles (side, classname, type, playerid, alive, active, inventory, color, plate, gear, damage) VALUES ('civ', 'C_SUV_01_F', 'Car', '76561198007151714', '1','1','"[[],0]"', '35', '893285','"[]"','"[]"')
Your query to insert is referring to "playerid", however the column has been called "pid" for a long time, it is likely that the SQL file you're using does not match the framework version that you're using. You'll need to correct these query references or use the correct file combination.