In college we made water balloon slinghots using multiple strands of surgical rubber tubing that were good for 80 yards easy. Needed five guys, two at each end and one to pull and fire. Not that anyone would do that nowadays, they’d deservedly get arrested! ;)
Lol.. just line those paint filled water balloons up to make a blue line of individual splats...
Redneck striper... 5 gallon bucket with removable stopper in hole drilled down low or on the bottom... strap bucket to the tailgate so it’s suspended past the bumper. Test with sand to see the rate of flow. When filled with paint and ready to go and in position at a stop sign, pull the plug and let it flow as you drive.
I know there’s a way because a busted can of intense pink panther colored paint put a quarter mile stripe on a road down here that lasted for years, and that was an accident.