I got my platform from wheelsfeels.com. It is an awesome set up with sliding drawers and a sleeping platform that can easily be removed and stored behind the seats when not in use.
I am short so I sleep without the extension folded down, but if you are taller you can run the front seats...
I got it off amazon and got a months subscription. I turned off the engine noise, increased the blinker from 3 to 5, and turned off the front seat belt alarms. I travel Texas a little, will be in Houston Sunday eve/Monday Morn, If anyone is close and would like to use it.