why do race cars have that mesh netting in the driver side window

To keep the driver is arms in the window in case of a crash.

So that in case the driver were to hit a wall driver side his head would not hit the wall. Recently they moved the drivers seat closer to the middle of the car to help with this safety factor.

More precisely to keep body parts e.g arms inside the car if/when they roll.

Just in case the driver wants to stop and do some fishing.

if the car crashes and rolls then the window glass would be shattered and the driver could end up with an arm out of the window. not a good thing to happen when rolling, things could rip it off or mangle it badly.

LMAO debbie, wonder where they keep the bait:)