Get a webpart in the webpart gallery

I am trying to get a webpart from the gallary to add to a webpart page. It fails on the GetFile line saying that it can't find the file but the file is in the gallary. Is the code/path correct?

 SPFile myWebPart = newSite.RootWeb.GetFile(newSite.RootWeb.Url + "/_catalogs/wp/UserQuestionnaireSummaryWebPart.webpart");
    XmlTextReader read = new XmlTextReader(myWebPart.OpenBinaryStream());
     var wp = manager.ImportWebPart(read, out errMsg);
     manager.AddWebPart(wp, null, 1);
     manager.SaveChanges(wp);