I thought moving the body was the answer too, or that perhaps the body was moved using a car. But then I realized the Body Was also moved in the original series in the episodes Dead Weight, Double Shock, Any Old Port in a Storm (By Car), A Friend in Deed, An Exercise in Fatality.
For the moment, I'm otherwise stumped on this one myself.
Gregg and Rex came the closest to the answer. In all six episodes, the dead body is transported by means of the killer's car. That is why "Any Old Port in a Storm" is not included. Ric Carsini's body was transported in his own car.
If "Uneasy Lies the Crown" ought to be included on this list, please correct me. I do not remember whether the body of Adam Evans was transported in the car of Wesley Corman or David Sherwin.
David, I thought including "Dagger" was very creative of you. While Sir Roger wasn't actually in the trunk of Nicky's little roadster, he was still inside a trunk which was tied to the car!