Not sure if this is the one.

http://www.gizmag.com/road-shower-car-top/29085/

Looks good Janette. Just wondering if the attachment in the third photo, second link comes with it 

It is a great idea though and would probably hold enough water for a quick shower.

My first thought is that it would be very difficult to get to a higher hiace  van roof to fill it and pump it up.

I would love to see other ideas about solar showers

The real question is..Is it worth the effort and cost for the heat obtained?

Here are some calculations that I did some time back to give you an idea of just what temperature rise you could expect to achieve with the black pipe on the roof idea:-

1. Every metre length of 100mm diameter pipe will hold 7.25 litres of water.

2. Approximately 30% maximum of the surface area of that pipe will be exposed to direct sun at any time.

3. Therefore the surface area of the pipe exposed = pi x diameter x 30%, = 3.142 x 0.1 x 0.3, = 0.0094 sq metres for every metre length of pipe exposed.

4. Maximum solar insolation is approximately 1000 watts per square metre.

5. Therefore the maximum power input to the pipe per metre length would be 0.0094 x 1000 x 1 = 9.4 watts.

6. It requires 1 watt applied for 1 hour to raise 1 litre of water by 1 degree Centigrade at sea level, so 9.4 watts will raise 7.25 litres by 1.3 degrees for every hour that you have maximum sunshine.

This assumes maximum heat transfer, no wind loss, no re-radiation, no shade, and maximum sunshine for the entire time, none of which will actually occur concurrently in even perfect conditions, and especially not if you are travelling.

If you start with water at 18 degrees C at 10am, you will have water at somewhere less than 25 degrees by 3pm, after that it will cool rapidly.

Having too many showers at this temperature is sure to affect your sex life.

Better to boil a pot of water, add it to a bucket of cold, and use a solar shower pump.

Thanks for the figures Brian. I think the real thing had a flatter shape exposing more area and was metal again more effective than a home made pvc pipe.