The latest in GTA 5 mods craziness on PC is a mod that lets you shoot fireworks out of your car.
Taltigolt has a short video to show you all the craziness. There are a lot of flashy lights in it, so watch out if you suffer from epilepsy.
You can download it from here, though the links have been recently removed due to some reports of the mod being used to cheat in GTA Online. So until it becomes available again, you may only watch it on video.