Keep it on you.
If you are going someplace where you cannot take it, leave it home in a safe. If you are going someplace where alochol is being served and you are imbibing definitely leave it home. There is no such thing as a secure spot in a car including in a safe. As long as the car can be easily stolen or broken into, and that covers all of them except for the specialty security cars,, the weapon should not be left in it unattended.
Number one priority in having a weapon is using it only when needed to protect your life. Number 2 is making sure no one else gets it. If that makes it "incoinvenient" too bad, do not leave it where it can be stolen either for itself or as a bonus when your car gets boosted.