The Hauppauge diversity is controlled by the driver ( there is a little program from the company that lets you choose between diversity and dual tuner )
A good app I'm using and it embed's quite good is Splash Lite
http://mirillis.com/en/products/splash.html
In the future they also plan to make a TV only version
*My problem with VLC is that from my experience it crashes a lot when you have lousy reception , So it not really acceptable for car-pc usage..

