Porsche is expanding two on-demand subscription programs to several more U.S. cities and into Canada. The German automaker announced Thursday it will expand to Las Vegas, Phoenix, San Diego and Toront
<img src='http://tctechcrunch.files.wordpress.com/2010/07/picture-22.png' class="snap_nopreview shot2" alt="Porsche Boxster" />The electric sports car scene is heating up with <a href="http://www.crun