I have been giving your question some thought.
I am really at the point of I do not know what I do not know. What I have done with vehicles is so very simple. I have exited a stationary vehicle and engaged steel targets, using the vehicle as cover. I have done a couple of Simuntion scenarios around vehicles.
That said things I would like to try (and insurance, safety, practicality may make these near impossible)
Shooting while driving/while moving: through Drivers Side, Passengers Side, rear, and front windows from drivers side, passengers side, rear both sides
Shooting from different vehicles: car, van/truck, motorcycle (driving and rear seat)
Shooting at moving targets from vehicle (vehicle to vehicle)
Lighting Conditions: sunny day, low light, low light with rain or snow, in too much light (think night with way to bright emergency vehicle lights and flashing light, in a construction zone, with road flare smoke)
Deploying different weapons platforms. handgun, shotgun, rifle, SBR, SBS, AOW, pistol braced platform. From lock box, seat, holster. This would need loading drills, which is going to be different for jurisdictions.