To get this achievement you will need to delivery 30 specific vehicle's to a garage in the island Bohand.
After unlocking the Alderney safehouse and the exotic exports side mission you will receive a phone call from Brucie, who introduces you to his friend Stevie.
All you have to do is wait for a SMS from Stevie showing a vehicle and giving you directions in order to find it.
Reach the vehicle, steal it and take it to Stevie's garage.
Differently from the Exotic Exports, the more the vehicle is damaged the less money you will receive, so drive slowly and use the Pay'n'Spray garages if you damage the vehicle (only if you care about the money).
Once you have delivered the 30th an last vehicle to Stevie the achievement will appear.
Check the video the the link below and look for the name of the vehicle from the SMS from Stevie in the description of the video to find the locations of the vehicles.