Unfamiliar SUVs on Summit Avenue

I just wanted to give you a heads up. A neighbor on Summit Avenue saw a couple of unfamiliar (non-residential) SUVs - one blue and one black - parked in front of my house (12 Summit) and the rental (16 Summit). The neighbor then saw a woman get out of the SUV parked by me and bring a suitcase to the man in the one near 16 Summit, then a few moments later take the suitcase back and both SUVs then leave. This struck the neighbor as odd. She is going to try and notice if they come back today or tomorrow and will try to get their license plate numbers. It could be nothing, but it's a little weird the way she described it and she felt it was worth her looking into. I am home sick today, so I will keep my eye out as well. A residential street like ours is an odd place to do a materials exchange, not exactly the kind of place you'd coordinate with someone to meet.