Heathrow to Gatwick Airport connection

<p>A friend flying British Air from Paris into London Heathrow needs to transfer to Virgin Atlantic flight out of Gatwick.&nbsp;&nbsp; Other than hiring a private car between the two airports or taking the train with transfers through&nbsp;central London, are there any other options?&nbsp;&nbsp; I struck out trying to search the ITN website.&nbsp;&nbsp; He and his wife appreciate you help.</p>