Mine

public OnPlayerStateChange(playerid,newstate,oldstate)

{
if(newstate==PLAYER_STATE_DRIVER){
if(GetPlayerVehicleID(playerid) == 7) {
GameTextForPlayer(playerid, "~w~Bring this car to the ~r~checkpoint ~w~to sell it!",3000,5);
SetPlayerCheckpoint(playerid,1678.8834,2318.4619,10.8203, 2.0);
gPlayerCheckpointStatus[playerid] = CHECKPOINT_SELLPLACE;
} else {
}
return 1;
}

{
if(oldstate == PLAYER_STATE_DRIVER || oldstate == PLAYER_STATE_PASSENGER){
DisablePlayerCheckpoint(playerid)
}

return 1;
}