i was able to get the asea by starting the single player game, load up a solo online session, started a new character, and i kept my car from the race tutorial every time. then i just had a friend hang on to it while i switched characters.
note:the race will be against other players, but the mission after will be solo, so you get your car you raced with
edit**also forgot that i had to let the intro video play a few seconds and exit to the dashboard. then when i did the solo session from single player mode, it would load the new character
edit 2**I got one using solo session, but I had to go all the way past simeon to get in a new session and give the car to inZombiiac. Maybe i selected invite only before. it works though, just a little more time consuming