Stealing guns from cars is a big way that guns go from being “legal guns” to “illegal guns.”
Here in Texas, I know a lot of people keep a gun in their car. Honestly I don’t know what good it does them. The gun is rarely (never?) on their person, crimes in a car aren’t that frequent, and if one does happen most people who keep guns in their car keep them in some useless state (e.g. bagged up, boxed up, etc.). So basically it’s just a 4-wheeled storage crate, where you bring the gun to the thief.
The unfortunate thing is a lot of laws force law-abiding citizens to behave in this manner. You might have a concealed handgun license but now you need to go into a building where you cannot legally carry it, so you are now forced to leave it in your car. It’s just bad feeding worse.