Of course it's reliable enough for a car gun. Far better question, IMO, is why need a car gun? Can you not legally carry?

Anything left in a car routinely is begging to be stolen. Depending on your state laws, a loaded handgun in your car puts friends or family members at legal risk of being in the car if they are not licensed to carry.

Just saying... with a handgun on me all the time, a car gun is a poor idea. (For me.)