OP: Your post reminds me of my college days, when I drove for the university's transit system (35 ft. transit buses) and rode a bike to get everywhere else. I would go months between times for driving a car.

Did it feel weird to get behind the wheel of a car? a little, but I remember adapting pretty quickly. When I finally got a car, my senior year of college, the entire transition effect went away. I experienced something similar when I rode a motorcycle 95% of the time - switching to the car always felt weird (slow, clunky, enclosed). I don't recall the claustrophobic effect, but I do remember the feeling of being too low and not being able to see.

Honestly, though, my hardest ever transition was when I got used to driving light duty military vehicles in Haiti. The return to driving in the US was freakish (lane discipline, signalized/controlled intersections, real roads, folks not immediately yielding to my CUCV or HMMWV...)