[park4bmx]

pawn Код:

if(GetVehicleModel(VID)==596 || GetVehicleModel(VID)==523 || GetVehicleModel(VID)==599)//it needs to be "||"
{
    if(oldkeys & KEY_CROUCH && newkeys & KEY_CROUCH)
    {
        return 0;
    }
    else if(newkeys & KEY_CROUCH)
    {
        return cmd_siren(playerid, params[0]);//the params holds an Array!
    }
}

it needs to be "||" you cant be in multiple vehicles once.
edit
if this cmd doesn't have any parameters then why have the params ?

pawn Код:

COMMAND:siren(playerid)
{
//cmds stuff
}

//Then use it likes this with the reurn
return cmd_siren(playerid);