10 of 10 Vehicles are exclusive, limited availability vehicles with only 10 ownership slots available per vehicle.  

Once all 10 ownership slots for a vehicle have been claimed, that vehicle will no longer be available for purchase.  

Check the Premium Vehicle Shop in game to see which 10 of 10 vehicles are currently available and how many slots remain.  

These vehicles are designed to stay rare, so once they're gone, they're gone.