Ok - I've heard you blokes with ocky straps, bits of wire, bits of rope, and now home made chutes (well done!)
I use the "handfull" grass chute. It requires no modification from standard, fits any mower, costs nothing and takes up no room on the truck.
???????
1-Start the mower and cut a few meters of grass. - stop blades/turn off mower.
2- Grab a "handfull" of cut grass and open the rear flap.
3- Jam handfull of grass between flap and chassis up near the hinge of the flap, let flap close to trap "handfull" of grass in place. A handfull will normally keep the flap open about 3-4 inches, double handfull will jam the flap open about 6-7 inches. any more and you risk hitting your legs with rubbish.
4-Cut grass with mower.
5 - when finished cutting grass, lift flap and remove "handfull" - put mower back on truck.
I was gunna patent it on "the Inventors", but some dumb b!tch wasn't satisfied with "what colours it comes in "