Go upwind more efficiently!
The sets of telltales on your genoa are the key to adjusting your jib cars. If the top set are stalling before the bottom set of telltales, pull the cars forward. If the bottom ones break first, the cars are too far forward. They should break at the same time. If it’s windy, consider moving the cars back a stop or two, which allows the top of the jib to blow open and depower itself.