I'd make a 90 degree turn to walk between a couple of parked cars and get a look at them. Depending on what I saw/thought at that point I'd probably continue on to my car while keeping an eye on them and keeping other vehicles between them and me. At this point I'd probably have a hand on or near my gun.
Hopefully at this point I'd just continue on to my car in a high state of alert, get in, lock the doors, and watch them walk past to their car.
If they tried closing the distance prior to my reaching my car I would loudly ask if I could help them. If my tone and question didn't stop them things start to get tricky. I haven't seen a weapon, but two on one is in my opinion a deadly threat. However, I don't know if the police or DA will see it that way. I'd probably be hesitant to use deadly force, which in turn would make me hesitant to draw my gun. If I felt threatened enough, I would, if I didn't, I wouldn't. Hell, as much as I don't like to say it I might very well run. However, if I chose to run and they gave chase I can almost certainly say the gun is coming into play at that point, hopefully after I find a nice big van or truck to duck behind.
A lot of my action would depend on my rating of these two men as a threat.