This video is a tour through my 2009 Honda Civic which I have managed to outfit with amenities for living. Hopefully this will give others the idea on what's possible to do with their cars.

Some stuff not mentioned in the video:

I have a cooler in the front seat. It fits a big block of Ice and keeps stuff refridgerated for 4 days. I sometimes buy milk or meat to grill and put it in there.
The glove compartment is stocked with first aid supplies. Theres also pockets on thhe doors filled with things and I do have a battery jump starter/spare charger in there behind the spare water jug.
The whole thing cost around $400-500. That includes the wood, screws&washer, hinges, latches, magnets, curtains, water carrier, food safe tubing, carpet and memory foam. I also bought the grill for $120 but thats something I wanted anyway, for camping.