Smith Airweight J-frame.
If no passengers (the 99.9% usual) I park it on the seat next to me, in an upside-down baseball cap so it's less likely to slide off in a hard stop. If it's a really hard stop, I have other problems besides the gun sliding onto the floor.
The hat stays in the car, basically its only function in life, and I jokingly call it my car holster.
Now, this is Colorado in 2019, where a gun on a car seat is not a problem. WTF it will be like in five years is another problem, with the State recently turning Commie. When I get to my destination, I have no problem pocketing it while standing by my open car door, since the gun can be "palmed" easily and doesn't look like anything in particular.
In the unlikely situation where I will have a passenger, I'll just keep it in my pocket and put up with the possibility of a sneak attack.