Maybe in MD, but in most of the free states, reasonable fear of loss of life or limb is the standard. Doesn't matter if it's actually real or not, the shooter would deservedly get off scot-free.
Not all of us have to rely on the police to protect us.
I really really doubt that you would get off scot free ANYWHERE under the circumstances described here.
You wouldn't if I were on the jury. I support both packing and using your firearm for self defense, but engaging a target in another vehicle is stupid 99% of the time in my opinion. If for no other reason than you can NOT BE SURE of either your target or what is beyond it.