Hitting Home aka Obsessed (1988 TV movie) starring Kerrie Keane, Daniel Pilon, Jackbo Tierney, Saul Rubinek (as the on-the-run driver)
From IMDb: Canadian businesswoman Dinah Middleton is devastated when her son, Alex, is killed by a hit-and-run driver. When the police fail to turn up any suspects, she turns private detective to track the killer down. She traces the murderer to New York, only to discover that the crime is not covered by the extradition treaty between Canada and the United States. She becomes obsessed with bringing the criminal to justice. / The boy's body gets caught on the car, and he is dragged for some distance. I remember this movie vividly, having seen it at least twice on Lifetime Movie Network.