Every state is different regarding guns in a car Mike. You are in Texas, so the gun must be concealed. In Virginia it must be in plain sight.
It makes sense to get a Concealed Weapon License whether you will ever use it or not. It protects you every single time from frivolous actions. You need a license for each firearm you may have on your person. I recommend the License because you have to qualify with the weapon to earn the License and that means you respect the gun.
First thing to do whenever placing a gun in the car, always put it on Safety. Small thing, but it sends a message that you are safe to anyone who questions your intent.
If you have a "secure" holster, meaning one with a snap that keeps the hammer in place so the weapon cannot fire, that is yet another indicator for an Officer that the gun is not a threat. In fact, I recommend a holster at all times rather than a free weapon any time you are in a car or not. It is easy for a lawyer to defend you if you do run afoul of an Officer. Even if the gun is loaded. Another reason I do is because sweat and body oils are bad for the gun. The holster protects the gun too.
To answer your question though, when I travel somewhere to a range with a gun that I do not have a License for I unload the gun before I ever take it to the car.
If it is a pistol with a magazine I remove the magazine and I slide the receiver open if I don't have a holster for it. I holster it if I do, and secure the hammer. If you can keep the receiver open and in the holster do it. This shows an officer that the gun does not have a round in the chamber, and is not in the car to be used in the act of a crime.
It is better to put the gun in a protective case in the trunk and the ammunition in the glove box. The simple explanation for the gun being in a case in the trunk is that it is out of reach for a driver or passenger. No wrong intent can be assumed.
If it is a revolver I unload the wheel and either leave it flipped open if it does so, or in a secure holster. Bullets in the glove box.
If you ever put the pistol in the glove box rather than a case in the trunk, unload it and lock the Glove box. It speaks to intent again.
No officer will ever mistake your intent if you do these things, or if they do you will win any fight for your rights.
One last thing, never, and I mean never, have one in the car if you have been drinking. I don't mean drunk either. I mean drinking. Alcohol, firearms, and driving equals extreme paranoia.
