You can't open a Object Extention (.qar) like it is a normal QVW File. As far as my experience goes, I think the only known way to use it is to click the icon "Turn on/off Webview" and right-click on a blank space in the dashboard, choose "New Sheet Object", Select "Extention Objects" and there you'll have the access of your QAR File.
Also see these post:
And this vídeo:
qar file is the extension file this is not a application.
change your application into webview
right clik ->new sheet object -> extension ->
there have you google map just track it