This is not legal advice and it is only to the best of my knowledge:
As mentioned already, drinking and guns do not mix. Intoxication is in the opinion of the officer, not just a breath test. Ask yourself if you are prepared to make a hard and fast rule that excludes all alcohol for all parties in the car period.
Also, the MPA requires that your gun be in your car or a car under your direct care and control. It is my understanding you can't take it with you to ride in your buddy's car.
As mentioned, you also should be aware of the criminal history of anyone in the car. Should you have a felon or someone on probation in the car and the gun is accessible, that is a problem for that person and perhaps for you too. It is illegal to make a gun accessible to a felon. "Accessible" might come down to a DA's opinion. A lock box that only you have the knowledge of how to open is a very wise thing.
Secure the gun in a proper holster and restrained so that a car accident does not mean it can go flying all over the car to end up who knows where.
Illegal behavior done in/around the car can carry a heavier charge just because the gun is present and instantly makes the presence of the gun unlawful carry.
Do any of your buddies carry/use illegal drugs? Might they stash them in your car and deny ownership during a traffic stop? Getting into an altercation with someone is to be avoided.
There are federal laws prohibiting entry onto Federal property like Post Office parking lots or any land/water owned by the Texas Army Corps of Engineers. Don't even drive onto those properties with a gun in your car so you will need to check on who actually owns parks and lakes you want to go to.
Bottom line, you will need to behave with significant awareness and self control well beyond what is normal for the typical person your age and extend that to those who ride in the car with you. Losing sight of any of these things can put your ability to carry a gun ever again in the future at risk as well as cost you unreal sums of money for legal expenses. Worse, it can mean instead of you using the gun to defend yourself from a criminal, your gun ends up taking an innocent life. Obviously, you care about these things or you would not be asking questions here. I commend you for that wisdom.
I know this all sounds like a lot of confusion but it is important you don't just take someone's opinions (mine included), go to the laws and read them, go to reputable dependable sources for info, be sure you understand the laws not just for car carry, but the deadly force laws on when you can legally defend yourself. The idea is for the bad guy to go to jail, not you or your buddies. Hope some of this is clearer than mud
AND, if any board members feel I am in error on any of this, Please feel free to point it out.
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