...the days of just loose-carrying a chambered pistol in my car are over for me.
Not necessarily, you have several options open to you that would not require unchambered carry. Here are several off the top of my head.
1. Most, if not all, cars have a system that allows you to lock the glove compartment. You could leave your firearm in the locked glove compartment.
2. You can install a separate lock box to hold your gun when you are out of the vehicle. This also has the benefit of possibly securing your gun against theft if the vehicle is broken into.
3. You could carry a pistol which incorporates a magazine safety. When you remove the mag, the gun is essentially inert, even if a round is chambered. You can leave the gun in the car and keep the magazine on your person.
4. You can keep a container in the car, put the gun in the container and leave the container in the trunk. That would keep anyone in the passenger compartment from accessing the firearm.
By the way, you should check your local laws. It may be a criminal offense to leave a small child unattended in a vehicle. In my state, a child under the age of 7 may not be left unattended in a vehicle for more than 5 minutes.