As the entire encouter was a ruse maybe the person came up with a very long crazy story to convince DNV to go someplace else. Or, if it was a person well known to DNV they might have simply been chatting before leaving. As DNV didn't put her foot on the gas and try to escape that we are aware of then whomever she was talking to in car 3 must have been successful in convincing her to go someplace else. Also, if car 3 people were known to DNV and they said do you want to have a smoke or do you want some e or molly maybe she could have done that then too.
I've struggled in a major way to figure out why she stayed there for so long and then by all accounts simply drive away? If the goal of car 3 was to take DNV and her car then the drugs could have been a way to make this happen IMO. This is a reach as we are trying to fill time at a dark gas station with next to no information. I think the only thing we do know is that DNV stayed with Car 3 either because she felt ok about staying or was compelled to stay via being blocked into the Shell station.