--boundary
Content-Disposition: form-data; name="file.xml"; filename="file.xml"
Content-Type: text/xml
Content-Length: 1665


<XML>
.....
</XML>

--boundary
Content-Disposition: form-data; name="licensePlatePicture.jpg";
filename="licensePlatePicture.jpg"
Content-Type: image/jpeg
Content-Length: 7231

<BASE64 ENCODED IMAGE HERE>