The bull-nosed 1920 Morris Oxford tourer was originally owned by Mr Ewing's grandfather Edgar Ewing, from Totara, who bought it at the A & P Show.
He sold it in the late 1950s to Archie Johnston, a teacher at Waitaki Boys' High School, and he later passed it on to his daughter and son-in-law in Christchurch.
In the late 1990s, one of Lloyd Ewing's cousins was at the Canterbury A & P Show and saw a brass radiator that "looked a bit familiar".
The car was for sale and, although there was interest from the United States, the family managed to secure it.
It is now owned by Lloyd Ewing and two of his cousins, in a family trust.
Mr and Mrs Ewing brought it south last weekend for the North Otago Vintage Car Club's 50th anniversary rally, incorporating the Windsor rally.
The car carried badges from previous Windsor rallies.
It was special that the car was part of the family history, Mr Ewing said.
