Hi Jaydee.
Im unsure about bubble wrap for insulation.
The standard for any insulation to reflect heat needs to be reflective. Ie. Similar to the make shift sun visors we put up in our wind screens to keep the sun out.
We have a full set of fitted window covers in the back of our cruiser and it keeps the temp pretty consistant, on hot and cooler days.
Hope this helps.
Kezngaz.

I line rear windows of Patrol with "Corflute" salvaged from Election/Real Estate signage to reduce temp when carrying Waeco Fridge in rear.

Heat travels in thee ways, radiated, convection and conduction. Heat mainly gets to us via the sun, it is radiated, travels trough vacuum and through any clear (ish) material. To stop radiated heat you have to reflect it back. Convection heat travels by warm gas, or liquid moving around, e.g. warm air raising, so its all ways hotter near the ceiling. Air currents, water currents etc. Then heat travels by conduction, try picking up something hot with gloves, its OK for a while, as the material of the gloves is a poor conductor of heat, now wet the gloves and try the same trick, you will get burnt, because water is a good conductor of heat.
So in order to tackle the heat loss problem, you have to look at what kind of heat you want to stop loosing (or gaining).
At night time there will be very little radiated heat so reflective surfaces would do nothing. So you have to look at convection currents, and conduction. Air is a poor conductor of heat, so the Europeans double or treble glaze their windows, as are some in the RV vehicles, this puts a layer of air, between the conductive layers of glass or plastic, and so conduction is reduced (but not radiated heat).
The other heat we have is convection currents, to stop this we need to stop the air (or liquid) from moving, we do this by using foam (the bubbles of air in the foam), this would by the way stop both convection, and conduction, curtains help stop convection currents. However any way of trapping the air helps reduce heat loss by convection, and so using bubble wrap would be ideal, several layers of bubble wrap, but remember heat rises by convection currents, so the roof vents need to be treated as well.
I use 50mm foam in the roof vents, to stop heat loss or gain and have a layer of reflective foil glued to the outer side to use when the sun is shining.
Hope this helps.

Hi JayDee

Ive been looking for the silver bubble wrap as well must be some thing they only sell in the USA
If some one know where to get it please let me know where they sell it
I only need a few meters

Cheers John

CC you can get the "Silver Bubble wrap" in the form of Windscreen sunshades at most $2 shops - buy several and cut to suit rear.

If Air-Cell is what I'm thinking of, my neighbour just used it under the new metal roof for his workshop. Brilliant stuff. Quite thin but still in excess of R2.
Maybe roofing suppliers may be a possible source. Assuming of course we're talking about the same Air-Cell

Jim

If you get some Corflute (Election/Real estate signs) + $2 shop tin silver spray paint - cut to size/shapes.

@ Possum 3

Hi Collin

Thanks for giving me the right product name
found some on Ebay


Cheers John