UPDATE FOR USERS WHO HAVE MULTIPLE STORES, FEEDS and USE AN AUTOMATED SERVICE
Ok, so I have been working with Godatafeed for this since they manage all my clients feeds, have awesome tech support and we can have a layman conversation. We simply take the XML, bring it into the Godatafeed app, map all the basic fields, then create some custom rules from the various fields below. We end up creating the Google SEO friendly URL since the actual URL is not in the XML.
Custom Condition Example: http://www.YOURSITE.com/ + [Product Name Short field] + -p / + [Product Code].htm
Notes:
If your having issues, drop me a comment.