The temptation is to take the fact that the drivers of the two cars have not come forward, and to reach the conclusion that the two cars MUST be relevant.Koios, the owners of the two cars have never come forward. Whether they were visiting a pole or whatever, they have never answered the request by police to identify themselves and state what they were doing in Benaroon Drive that morning.
That is a risky assumption to make, because I think by far the commonest abduction scenario is a lone perpetrator, who cannot drive two cars at once.
I can find many cases of abduction which involve a vehicle, but none that involve two vehicles simultaneously.
Here is a useful reality check - has there ever been a case of an abduction by two people, who take two vehicles to do the abduction?