Jquery XML parse errors

I'm trying to figure out what's going on here.

//JQUERY

for(var i = 0; i < truckOrder.length; i++){
    function getDetails(t){
        return $.ajax({
            url : 'groups/group_'+t+'/content/quickview.html',
            type : 'get',
            async : false
        });
    }

    getDetails(truckOrder[i]).done(function(result){
        var xml = result;
        xmlDoc = $.parseXML(xml),
        $xml = $(xmlDoc);
        //quickfilter
        $qf = $xml.find('quickfilter');
        //quickprice
        $qp = $xml.find('quickprice');
        //quicktitle
        $qt = $xml.find('quicktitle');
        //quicklook
        $ql = $xml.find('quicklook engine');

        var newTruck = {
            quickfilter : $qf.text(),
            quickprice : $qp.text(),
            quicktitle : $qt.text(),
            quicklook : $ql.text()
        };

        truckDetails.push(newTruck);
    }).fail(function(){
        console.log("There was an error");
    });
}

//XML

<?xml version="1.0" encoding="UTF-8" ?>
<quickfilter>
    2015 intM cumE 13T apuNo
</quickfilter>
<quicktitle>
    2015 International Lonestar
</quicktitle>
<quickprice>
    $15,000 down, $2,595/60 months
</quickprice>
<quicklook>
    <engine> Cummins ISX 450HP</engine>
    <transmission> 13 speed</transmission>
    <features> Aluminum Wheels</features>
</quicklook>

I'm trying to parse multiple xml files, and build an array of objects out of them. When I have been trying to parse the xml files however I get an error like this Uncaught Error: Invalid XML:. I did some research on it, but I never really found anything that helped. This is kind of my first time working this intensely with XMl and jquery together, so any help would be much appreciated!