Hi All,
Have just spent a few hours this afternoon making up some rear window guards to keep any errant stones from ruining future holidays. I thought I'd post some info up here as it might assist someone else considering doing something similar.
Although the Tambo has a an excellent stone guard I wanted to use something to cover the back windows. Tambo stone guard:

I looked around at the commercially available rear window products and thought they were a bit expensive so set about making my own.
In the end I bought two sheets of 900 x 600mm 3mm polycarbonate for $69 from Bunnings along with some Velcro Brand adhesive velcro dots ($7.95 for a 40 set pack) and some clear rubber adhesive buttons ($3.95 for an 18 pack). All up cost to make the window savers was therefore $80.90.
I used a butchers paper template to get the shape right and then cut it out with the jigsaw set on low speed using an offset tooth aluminium / plastics blade which I already had. The vertical and horizontal cuts that terminate in a drilled hole (done with a blunt drill bit at slow speed) allow the polycarbonate to bend with the curve of the window and the clear rubber buttons keep it off the glass. The hook velcro dots stay on the vehicle - which is ok as they don't interfere with anything (wiper just slides over them)
All in all very happy with the result! Would highly recommend making your own - it was dead easy! A couple of tips I picked up from researching the web prior to starting last night:
- Use masking tape top and bottom of the polycarbonate prior to cutting.
- Clamp the sheet close to the cut for the full length prior to cutting.
- Make sure the jigsaw is on low speed to prevent shattering and melting
- Use the 'Velcro' or '3M' brand velcro dots as they have better adhesion in the heat than the cheaper brands
- Use a blunt drill bit on low speed to terminate the horizontal and vertical cuts
- Remove the window saver when not towing as it may loose adhesion if sitting in the summer sun - no problem, just toss them under the camper when arrived
- The Velcro Brand dots come in a 40 set, so have some left over to carry as spare in the vehicle
Hopefully some others will find this useful.
A few photos of the finished product:




