To create your own super sticky wax, very carefully melt down a regular block of surf wax in an old pot and add tree resin (pine resin is the stickiest) and mix thoroughly.
Pour your concoction into a paper cup or even several small paper cups and let it harden somewhere cool.
This wax, like all waxes, will melt fairly easily in a hot car, so its best only to take as much as you think you'll need or pre-wax before you go.