[FuNkYTheGreat]

Saving the vehicle isn't hard, Just save it's float x , y and z where the player parks the vehicle and about lock, You'll be needing OnVehicleStreamIn function check it out and loop through all players and check the variable that if the vehicle id is equal to his private vehicle and it's locked then setvehicleparams and lock it,

and for destroying, use DestroyVehicle(playervehiclevar); and when player spawns load his data on variables of x,y,z,color and other vars,
Then create it again !

Easy !