This spring my wife and I decided to go on a cross-country, one month adventure, traveling from New Hampshire to Yellowstone National Park, and back. In the past we had camped in the back of our 2012 Prius V a few times - the first when we went camping and I forgot to pack the tent poles! But the rear seats in the Prius do not fold down totally flat, and the seats take up precious room that we would need for storage. So I decided to convert the Prius to a camper.

This project is fully reversible. The platform can be removed in one piece for storage, and the seats can be easily re-installed. Total cost should be around $30.

Materials list:
1x3:
2 @ 46.5”
2 @ 25”
1 @ 23.5”

2x2:
2 @ 15.625”
2 @ 12.5”

3/8” plywood:
18 x 48”
16 x 48”

Carriage bolts:
8 @ .25” x 2.5”

2" and 1" finishing nails

hinges and short (aprox. 1") bolts that fit the hinges.

Tools: circular saw, drill, bits, wrenches, hammer, stapler, clamps.

I built this frame light and small because my wife and I are short (5”3”) and light. If you are going to use this
for hauling heavy items, you should beef up the frame with larger lumber.

Step 1: Remove the Seats

To remove the seats, I followed the instructions on another Instructable. It was easy, and the seats were remarkably light and easy to maneuver.

The bonus was that when I went to purchase the plywood, I was able to fit it, cut in half, through the backseat door!

Step 2: Build the Frame

Build the 48" x 25" frame out of 1x3's. Join with glue and 2” finishing nails.The legs are 2x2's. Shorter legs in the back, longer in the front, and the legs are bolted to the inside of the frame.

Step 3: Double Check the Leg Length

In order to get the correct length of the legs, I used a straight edge inside the car and clamped the legs on. This height could vary depending on the year and model, how thick your carpeting is, and the thickness of your plywood, so check your height before proceeding. Shorter legs go in the back.

The back legs fit perfectly in the area of plastic that I had to cut out with my Dremel when I removed the seats.

Step 4: Add Legs

Remove the frame from the car, place upside down, clamp the legs, and drill 1/4" holes. Fasten each leg with 2 @ 1/4" x 2.5" long carriage bolts.

Notice how these bolts are too long? They're ones that I happen to have on hand. I cut the bolts down later with a Dremel to prevent damaging our stuff.

Step 5: Assemble the Top

I made the total length 71": 34" of plywood plus the way-back of the car is 37". You must adjust your front seats to a comfortable position and measure how much room you have for the platform. We're short, so it worked out perfect. Cut an angle on the back corners of the 16 x 48" plywood to match the way-back. You need to get the plywood snug against the way-back.
Attach the 16 x 48" plywood to the frame with glue and 1" nails. Notice how it hangs off the back of the frame and rests on the lip of the way-back.

Step 6: Hinge the Lid

Attach the 18 x 24" plywood piece to the frame with hinges. I recycled some old hinges I happen to have. Bolt them to the plywood for strength.

Cover the hinges with duct tape to protect air mattresses and sleeping bags, and cover the bolts to protect items you will be storing underneath.

Step 7: Finishing Up

Connect the legs to the frame of the car with wire so that it will not shift during sudden stops. I used screw eyes on the back legs and connected to a plastic post I found under the trim. The front legs I wrapped wire around the legs and through some holes in floor.

Cover the plywood with fabric to protect air mattresses and sleeping bags from splinters.I used some scrap fabric I happen to have and attached with 1/4" staples.

Step 8: Conclusion

We just returned from our trip and the Prius camper was a success! We camped in it 24 out of 28 days. The weather wasn’t great - much of the time it was cold and rainy. But we were warm and dry (at least when we slept). The frame never moved or broke or caused any problems. We were able to store most of our gear under the platform and access it when we needed it. We used 2 Big Agnes backpacking air mattresses (they are only about an inch or two thick, but very comfortable) covered with a double bed sized foam mattress topper. The mattress topper was about 12" bigger than the platform, but that was no problem. It was very comfortable. And not too thick, which helped with headroom. Too high of a mattress will take away from the height. We were able to sit up and read, but again, we are short.

I also made curtains and window screens which I'll add instructions for when I get time.

Hope this helps anyone who wants to go camping in a Prius V. Just remember not to block the battery vent when you pack.

Happy trails!