Add css class to RGP Widget plugin

My theme has some nice styles for the widgets based on class="vcard hoverable"

I'm trying to get those styles to apply to the recent global posts widget and I think it would be easier to edit the php file with a div class than it would be to dig through all the css and copy it over.

I tried adding <div class="vcard hoverable"></div> to the file but I keep getting errors. What section of widget-recent-global-posts.php needs to be tagged with this to apply this class?

Or, to make it upgrade friendly, is there a way I can add something to my functions.php that will add the class to it automatically whenever the rgp widget is displayed?