GProduct Review Feed
This extension for Joomla 3.x and Virtuemart 3.x creates an XML feed of your Virtuemart product reviews, suitable for submission to Google Shopping. The feed format is compatible with the Google product review feed specification described here: https://support.google.com/merchants/answer/6171899?hl=en-GB
The feed works with the native Virtuemart reviews system and provides an easy way of submitting a feed, the XML file is created automatically in the correct format. You can choose to submit either a full feed or an incremental feed, and can mark individual reviews as spam or deleted. You can view a tutorial here, which explains how the admin interface works.
You can see an example feed here.