I've spent about 450 nights in the van since September 2013. I've installed a Webasto Airtop 2000 heater, an additional 6 leisure batteries, 2 skylights, a hifi system, numerous USB/charging points, 240V via a small 300W inverter, covered the floor in Altro safety walkway flooring, have installed numerous cooling fans and carpeted most of the walls and the roof. Keeping cool in the summer is the biggest issue and if doing this over again I'd add even more insulation which would help to keep the interior cool. Future modifications will include a solar panel and insulation panels for the side windows. I'm currently working on a system that will allow me to keep the roof vents open but also allow me to keep the van dark inside, useful for when I'm sleeping during the day time.