The trickiest things about carrying inside a vehicle are being mindful of changing laws driving cross country, being able to access the arm while driving and ensuring it remains out of reach of others.
This year I’m packing a K-frame, S&W Model 19 Carry Comp. The K-frame conceals easily with a vest or coat, and I like packing a .357 Magnum. The holster choice for carrying this 3" Model 19 was easy for me Simply Rugged’s Sourdough Pancake.