Triedaq
Visqueen is a tradename for a plastic film. It comes in different thicknesses.
I knew it was a plastic film but I did not know it was a tradename over the years I maybe heard it called that less than a half a dozen times I thought it was just a regional dialect.
We always kept a couple big rolls in the emergency kit to cover equipment in event of a water leak. Boots, gloves, masks, tape, flashlights, etc. etc. Can’t remember everything or opening a sealed kit. If we would have asked for Visqueen at the lumber yard, they probably would have sent us to the pharmacy.
"Bing,
If we would have asked for Visqueen at the lumber yard, they probably would have sent us to the pharmacy.
Probably would do the same here. 
Yup!
When the support struts on my Chevy Citation failed after ~4 years, I opted to use a cut-to-size broomstick, rather than spend any more money on that rapidly-deteriorating POS.
After 13 years, the OP’s Yaris may well be in better shape than my Citation was after just 4 years, but if the OP is considering replacing this vehicle w/in the next couple of years, the broomstick solution might make sense for her.
Funny you should mention this! lol. My father, a retired mechanical engineer, former antique car rebuilder, and bona fide handyman happened to have a 4-foot furring strip that has been working perfectly to prop the hatch. Even in the middle of loading up my hatchback with boxes for moving. If my dad is able to fix it on his own, for just the price of parts, then I’ll likely fix it, but otherwise, this janky piece of wood is working well!
Planning to buy an electric car in a few years, so it might just be the best bet for now.