Thankfully, the tools we use continue to get better and more app specific. For example, Sketch lets us design more efficiently with its focus on creating user interfaces. Marvel helps us craft better prototypes with it being specifically for apps. Swift has been a revelation for the Apple ecosystem and has expanded developer interest considerably. Android Studio and now Kotlin are doing the same for Android apps. Firebase and yes, even Parse, now as Parse Server, helps developers build app-focused backends to bring apps to the market more quickly.
It does sag a little bit, but not worryingly so. As I mentioned, it often rests on top of the large plastic boxes I place underneath, and I put in a small wooden brace at the entrance. You could definitely build it slightly smaller, or put in a more substantive center brace — like a sheet of plywood that fits into the groove of the bed liner and is the exact height you want.
The refrigeration setup in your van is an area where you really do get what you pay for, whether you’re paying in money or in time. The best options are the most expensive. The cheapest options are a pain and/or don’t work very well. And if you try to save money with a DIY refrigerator setup, you could end up spending a lot of time on installation. 

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