When you park in front of your apt, this same car pulls beside you w/ a group of people that seem to follow you as you go inside. Do you hold your gun then?
I don't think I would drive home, if I thought I was being followed. Instead I would probably drive to the Police department, or find a public place as crowded as I could. Then I would call the police. I think In any situation like that, getting out of your car, or driving home, would automatically give the bad guys the upper hand.
How about if your walking to your car across a dark parking lot and notice someone eerily watching you?
I always look around at all the other vehicles, or people in a parking lot, whether it is dark or not. But, more thoroughly if it's dark. I even look under, and around other cars that are parked close to mine. If the parking lot is pretty empty, but there is a vehicle parked right next to me, or pretty close, when I'm about 30 or 40 feet away, I'll go down like I dropped something, or like I am tying my shoe, and I'll look underneath the other cars.
If I noticed someone watching me, I would definitely be watching them. If when I left, they left too - I would probably handle it as I described in my first paragraph.
If I feel like my life is in danger, and I can't put any distance between me and the threat(s), then I draw my gun.