If one eats bread or pas haba bkisnin in one’s car, is this considered kevias makom for bracha achrona? If one forgot to recite the after bracha while in the car, does one have to go back to the car to make the bracha achrona or do we say that since I had the din of a traveller and never was really kovea a makom from the start, I can just say the bracha away from the car as if I was making a borei nefeshot where there is no din of going back to the spot of eating?
A car is considered a separate “place” for purposes of blessings (based on the common function of cars, in which a person spends significant periods of time, and eats, drinks, etc.), and therefore one who eats mezonos in his car would be obligated to make the berachah acharonah in the car.
The halachah of somebody travelling applies to somebody moving from one location to another. Although a car moves from one location to another, the person inside stays in the same location–in his car–which is where the berachah acharonah must be made.