Be careful at Mayfair. If the mall ninjas see you they'll either kick you out or call the police as they have a No Firearms policy.
As for gun placement in the car I'd recommend keeping it in the trunk. The laws are fuzzy where this is concerned and the trunk is imo the best place to have it.
I carry a Glock in condition 3 as well. I do this so I don't make the rather familiar sound of racking the slide every time I enter or exit the car. Just alter your draw to include a slide rack. Make sure to practice this (gun empty unless you're at a range that let's you do holster draws).
Other than that, gratz on your first time!