[Niko_boy]

ye for that u will be needing a variable / a array:
a example ::-
<in command or place where player spawn vehicle>

pawn Код:

if( pVehicleSpawned[playerid] != -1 ) // this variable need to be set to -1 at player connect or at any other place required
{
    for( new i; i < MAX_PLAYERS; i++ )
    {
          if( IsPlayerInVehicle( i,  pVehicleSpawned[playerid] ) DestroyVehicle( pVehicleSpawned[playerid] );// will delete vehicle id the playerid had spawned earlier if it is not occupied by anyone 
    }
}
pVehicleSpawned[playerid] = CreateVehicle(...); // create new vehicle and store vehicleid as seen by server in the variable..for playerid
//end

i made a fs which come with some similar example:
see its part where i createvehicle: http://************/79ltguu