<init can_send_fuel='1' day='735440' user_agent=''><user default_car='59363292' tank='0' races_lost='0' gold='0' money='800' races_won='0' fuel_ts='1406212478' fuel_base='100' money_spent='3700''>
list($a, $b) = explode("default_car='", $xml, 2);
$default_car = intval($b);