I operate a home inspection business and often find myself between appointments wanting a place to type reports or just relax and eat lunch. I just replaced the motor and transition in my cargo van so it looks like I will be using it for a while. Lets make the best of it. Every vehicle interior is different with a little insulated foam board, a hot glue gut, and some door skins, you can make a template in which to cut plywood to make a nice interior. Please note: this is something to enjoy while safely parked. Do not drive on these seats as they are not approved for transportation safety.
Step 1: Step 1
Clean out your space and find some objects you can sit on and things to represent a back rest so you know how your body fits in the fan. I used my daughter's booster seat and some bricks. I showed me not to put the rear seat too far back or I would bump my head on stuff. Get a basic idea on how you will fit and then its time to foam it out.
Step 2: Step Two
I bought about two four foot by eight foot by 3/4 inch foam insulation board from a home improvement center. You can cut it with a cheap bread knife I bought from IKEA (Guys, return and clean kitchen stuff each night if you are in a relationship). I also used foil tape (any kind will do) and kabob sticks to manage the foam. I started cutting seats, back rests, horizontal surfaces to meet the needs of my lounge. Try to make the fit close using a tape measure but remember, I will show a trick for a more precise cutting template. I wanted a love seat to sit with my honey and another seat across from the love seat so we can play cards as a family and so I can converse.
Step 3: Step Three
I actually went as far making the third seat before I had the idea making the third seat fold flat and the love seat backing to fold down for a bed. That's why foam is great, room for mistakes.
Step 4: Step Four
Once you have the foam figured out, you are just one step away from cutting the plywood pieces. The interior of the vehicle does not have perfectly straight lines so you will need to make a more precise template to impose on the edges of your foam. Find a friend with a table saw who can cut 2 inch strips of door skin. Door skin is very thin plywood that you can strike with a utility knife and break off at the strike. Hot glue a piece of door skin along a part of the vehicle where a funky cut will occur. Keep cutting small pieces of door skin and glue it in place until you puzzle piece a template. Break off your puzzle and then lay that template over the foam template. Hot glue those templates together to make a more precise template.
Step 5: Step Five
Now that you have your templates you can cut plywood and screw it together. I am a no frills assembler, I just just use wood screws and go nuts with a cordless drill with a screw driver bit. I was given a little foam and made cushions. I asked friends from Facebook for decorating ideas. I also made a quick solar power station with a deep cycle battery, a transformer from a auto supply store, and a solar panel from an RV store. I used the same method in making the plywood box.