For those who are interested in using Sketchup to help plan your layouts, etc. I thought this video was a good description of how to start drawing up your van: (If you're new to Sketchup, I'd highly recommend going through the four 'Getting Started' videos here: https://www.sketchup.com/learn/videos/826 ) For those that don't know, there's a huge resource of shared models that are available to use in the '3D Warehouse'. The bits and bobs that I've drawn can be seen here (hopefully - let me know if not. I intend to add the #DIYCamper tag to them in due course.) I know that quilkin has created some models of common parts, too. Sketchup 'Make' is still free to use at the moment.