Windows 8.1 XML file saving

I'm writing a simple Windows 8.1 (Modern/Metro) Application and I'm saving data in XML file. The code:

 private const string XMLFILENAME = "fileName.xml";
 var myCars = buildObjectGraph();

 var serializer = new DataContractSerializer(typeof(List<Car>));
 using (var stream = await ApplicationData.Current.LocalFolder.OpenStreamForWriteAsync(XMLFILENAME, CreationCollisionOption.ReplaceExisting))
 {
             serializer.WriteObject(stream, myCars);
 }

It works fine. But... Where I can find this file? I searched it everywhere and I can't find this. And second question: Is it possible to save this file where I want? For example, on my desktop?