Depending on the tactial situation shooting from your vehicle. Might be your best and only option.
There are situations where one could find that the vehicle is not capable of moving stuck in traffic at a stop light is just one. Being out side ones vehicle could place one in greater danger like Mr. Denny found during the LA riots. Being inside ones vehicle offers better protection from edge and impact weapons then being out side.
Shooting and hitting targets from inside a stationary or even a moving vehicle is very possible.
Leaving in your vehicle, using ones vehicle as a weapon, dismounting are all options and might be the best depending on the tactial situation.
If any one else is interisted training in and around vehicles. PM me and we will talk about setting up training that meets your needs.
NRA,DOJ certified pistol,rifle,police shotgun and patrol rifle instructor.