The picture above is of my seat-back table with my wash basin and squeeze bottle on it.
The back seats of the Prius are removed. I made a platform on the Passengrr side (60%) for the fixed bed.
Behind the drivers seat (40%) side I have a seat I made.
I have a small wash basin. The kind they give in hospitals. I store it behind the seat where I sit in the back.
This is important. My side window curtain has a bungee that holds it tight against the door at the bottom of the glass. This is important because without it your body constantly rubs the curtain since the side body curves out on the side.
I hope you can see the bungee above.
The Washing Process:
I take the hot water in the thermos and pour some in the squeeze bottle to get warm water. I use this for rinsing.
While undressed and sitting in the seat I put towel on lap and basin on top of the towel.
I put warm water in the basin and use face cloth to wet my hair.
Then I use shampo to wash hair and with my head bent over basin I rinse my hair with water in squeeze bottle.
I have a separate towel to dry my hair.
With hair done I now sit on my bed and face towards the seat with the basin on the seat with my fear on either side. Basin still has soapy water from washing hair.
I now use soap and face cloth to wash body starting from top to bottom.
I end with washing feet in the basin one by one and using warm water from squeeze bottle.
I pour the dirty water from the basin in my waste water tank. Above is my waste water tank with funnel in it. It's a large detergent bottle.
I'm done! It takes about 1/2 hour.
It takes about a quart of water.
I have tried different times of day to wash and wet shave. I've gotten to the point that it works best in the early evening after dinner. This works best for me as the Prius is warm from the day and I may not have to run the engine. It also works as I often hike and I'm cleaner before getting into the bed sheet.
As I stated I wet shave sitting in the back seat too.
I want you to know that I'm 6' tall and I can doubt his easily and it can be done totally without getting out of the car. It is doable when stealthing as long as you are cautious about not moving fast in the Prius.
On my Travels this year I washed up like this in the Prius 6 days a week and it didn't bother me.
I saved significantly over going to truck stops for showers every couple days at $12.00 per shower. I tried washing like this for about 3 weeks without a shower without problems.