I'm been on a number of road trips in high school and college where the only place to sleep was in the, not always very large, car. When your young sleeping in a sitting position or slightly reclined isn't that big a deal but as you get older, and a better job, you find that sleeping like that is just not going to work for any reasonable amount of time. After the last trip my wife and I took, which was only a few days, I decided it was time to look into making our trips out a lot more comfortable.

I wont pretend that I didn't take a lot of inspiration from great instructables like these: The-MicroCamper-aka-Fat-Berta, Folding-bed-for-car-camping, Car-Window-Screen, Simple-Easy-Walmart-camping-Privacy-Curtains and Ultimate-Road-Trip-Car-Conversion-Honda-Fit.

I had a number requirements in mind when I started this project. First, I wanted to make it as inexpensively as possible and from parts that would be fairly easy to access. I didn't want to have to make any modifications to car itself. The frame and bed would need to be lightweight to keep fuel economy as high as possible but still strong, since I'm a rather large guy. Since the card we have is a Honda Fit, it needed to make the most of the little space available but also provide enough space for my wife and myself to sleep comfortably. I also wanted the entire frame to be easy to setup in the car and remove when not in use.

I accomplished this by using Compack 9-Leg Support Bed Frame, Full which is a full sized bed frame but folds down into a very compact form. Besides the frame I used LURÖY Slatted bed base, Twin and varies hardware odds and ends.

Step 1: Figure Out What Fits

Based on my requirements I had to figure out what sized bed would actually fit inside Honda fit. Measuring the inside with the rear seats down, I found that the car is the narrowest between the wheel wells in the back, being only 40 inches. This means that only a twin size bed would fit at the narrowest point. However, most of the rest of cabin space is about 50 to 54 inches wide, which is about the size of a full sized bed. Working with the theory that because a mattress is flexible I can fit a large one in a smaller space. I took an old futon mattress that we keep around for overnight guests and laid it out in the back of the car.

This mostly worked but the length behind the front seats is only about 3/4 the length of the full mattress and the back between the wheel wells ended up looking like a taco. Originally, I thought maybe I could just put the mattress back and we'd be good with the luggage on top and rearrange it to sleep. But to get the mattress flat I had to fold back the front seats and that added a major slope and lots of lumps to the front, besides the curve in the back.

Looking at this, I realized that I can fit the full sized mattress, which would provide enough space for both of us. But I had to lift it up get the mattress above the wheel wells to allow for more space in the back and go over the seats in the front.

Step 2: Figuring Out the Frame

Having figured out that I want to fit a full sized bed in a space of twin. I started looking at what other builders have done to make a base that fits in the back but also extents for sleeping when the front seats are down. I already assumed that the back seats would be down the entire time.

After looking around at available bed frames, I noticed that they are almost all made from 2 long rails that run the full length of the bed. I realized that this would work but I would have to leave the frame disassembled stretching between the front seats, not a preferable situation for long trips.

I realized that I really wanted something like what he did in Folding-bed-for-car-camping, with a stable base in the back with the bed on top and arms that swing out over the seats to form the rest of the bed when ready to sleep for the night.

I started designed something along this lines for my Fit but unlike the Element, there are not that many anchor points that could be used to create a stable base. As I started to fear I would have to create a standing frame from scratch, which would be difficult since I would want it make of metal to keep the supports thin to allow more space and overall, metal would be lighter wood since less material would be needed, I came across the Compack 9-Leg Support Bed Frame by Sleep Revolutions.

Step 3: The Perfect Frame

This frame had everything I needed and then some. The entire frame is very light, weighing less then 20lb and is since it folds up completely, it is also, by design, adjustable along the width. Also the way the support bars fold out to form the length of the bed meant that half the frame can be setup in back and the front supports can fold out over the front seats to form the sleeping position.

The reason for going with a full size frame, even though I can only use twin size frame in the car, is that I can now easily use the frame outside the car also, as an extra guest bed frame, no more sleeping on the floor. Or, if we do setup a tent we can have a real bed in the tent.

Next I just had to figure out what I wanted to use as a base for the bed on the frame. I considered using 2 pieces of plywood, one for the back and then having the other to put on the front section when in place. But again that would be heavy, I don't need a solid base and I wanted something with a little spring to make sleeping more comfortable. With this in mind I went with the LURÖY Slatted bed base, twin size from Ikea. Besides being much lighter, about 15lbs, it's also takes up half as much space, since I can just push the slats against each other under the mattress in the back and then pull them out to cover the full length when needed.

Step 4: Adding Storage Space

Having found the frame and base for the bed. Now I needed to make sure I had space for storage. I realized after reading the comments from similar instructables and having been in a rollover myself, securing loose items while traveling is critically important. The legs on the frame are exactly 6 inches tall, which is enough to have a level surface for the bed in the car but not really enough space to store much underneath.

I thought about just getting the plastic bed lifts that are all over online but after seeing reports of them failing spectacularly and randomly. I don't want to risk anything underneath being crushed, instead I decide to over-engineer taller legs for the bed. I took 1 1/2" perforated square steel tube, since the legs are 1 1/4" square steel, and made 4 legs of 12" each. This would provide a minimum of 12" of space underneath, which I thought would be sufficient for what we'd be taking.

Instead of just letting the frame rest on the tubing and to add a feet to better distribute the weight from the bed. I used carriage bolts, eye bolts, coupler nuts and electrical box covers. To make the feet, I drilled holes in the box covers just slightly larger than the size of the bolts, in my case 5/16. I then hammered the carriage bolts into the holes to make them square. This allowed me to just screw the feet into place after securing the eye bolt in place with the cross bolt and lock nut. As added protection for the car and the bed frame. I added thick duct tape around the top of the tube and around the edge of each foot.
After assembling the legs I found that to make the bed more flat in the car, I needed to adjust the height of the legs in the back and the front to lift the frame higher. With the way the bolts are assembled, I just have to use different length carriage bolts that connect to the feet and move the eye bolt up or down a hole, to change the heights of the legs.

Step 5: New Mattress

Really not strictly necessary but the futon mattress we have is 8" thick and has springs in it. It's fairly comfortable but far too thick for this use and it didn't fold very well. At 8" thick, that's 16" when folded in half which is a lot of space in such a small space. So, I replaced it with a 4" 100% cotton mattress. Also, 4" doesn't sound like much but again with such little space, every inch makes a different in comfort.

Also, since the new mattress is much easier to fold than old one. I now have the option to break the frame all the way down and fold the mattress in a "Z" in the trunk. This way I can now carry the bed and transport people.

Step 6: Additional Items for Comfort

Having slept in cars in the summer many times, it can very quickly get uncomfortably hot and stuffy. To counter this I make custom fit screens to cover the 2 front windows and the moon roof, which provides the most relief in the warmer weather.