Just put the paint scheme and the finished crew in your exports and imports folder inside the game.
Now go in the game, click Opponent Manager and select New from the right side about midway down.
Choose the Make from the dropdown, click ok.
Type in your name of the file and click ok.
Now in the top right type in your name, car number and sposor.
Now on the bottom right you see the car spinning, click import and select your paint scheme from the list.
Now on the bottom right click on crew and then import and select your crew from the list.
Now click save and confirm and your done.
Go back to the main screen, select Player info and then up in the middle select online or offline and then use the dropdown box to find your newly made car.