money

Have a full 10 car garage.

1: Take out the (free car) that you don't mind replacing.

2: Put that car back in the garage.

3: Walk out of the garage.

4: Take the vehicle I've spawned for you and then go into garage.

5: Replace the vehicle that you took out of the garage.

Steps done, you can now sell the vehicle. If you want more than one bike, go back to step 1!