Taxi Lisboa, a film recently released in Portugal, celebrates Macedo's world, focusing on his beloved car, in which he ferries around a curious batch of oddballs - a Spanish circus performer, an Italian pizza mogul; they might have been invented by Fellini but are mostly real people.
It was filmed last year, when Macedo was 93. In nearly 70 years, barely a day went by without Macedo at the wheel of his spectacular vehicle, making stately progress through Lisbon's steep winding streets and elegant squares, or bowling along the coast road to Estoril.
Macedo won the Best Actor award at Italy's Pescara film festival last November for a performance that follows no script and consists mostly of gentle quirky tales and encounters with friends on the road. Late last year he fell ill, and he died just before the premiere on 12 January - an unhappy coincidence that cynical commentators suggest could catapult the film to cult status.
He is remembered with amusement and affection. "He was a good man," reminisces Jesus Nunes, 61, a Lisbon taxi-driver for a mere 30 years, whose Volkswagen is far more sagging and clapped-out than Macedo's splendid antique. "He liked to drive slowly and carefully, so we always had to wait for him, but he never had an accident ... How he suffered with the potholes!"
The film, by the German director Wolf Gaudlitz, offers an unashamedly romantic vision of Lisbon, to the annoyance of some local critics, one of whom sniffed that the director, following the example of Wim Wenders's sentimental Lisbon Story, was "wearing Lisbon on his sleeve".
Bruno Cabral da Silva, the young Portuguese producer, concedes that "Germans have a very romantic image of Lisbon. It's so completely different from Germany. For them it's exotic."
Only six Oldsmobile cabriolets were made in 1928, and only three came to Europe: to France, Italy and Portugal. Macedo's alone survives, with the original engine, which has clocked up 2.5million kilometres. The clutch was replaced 20 years ago, and the canvas canopy 15 years ago after someone slashed it with a knife. Macedo henceforth never left the car unattended, preferring to eat at the wheel.
Augusto Macedo's burly son, Fernando, 65, an accountant, lives across the street from his father's old house in the Buraca suburb in Lisbon. He says his father cocooned himself in the car, his best friend. "He put the car first, ahead of his family. Every night he would clean it, look after it, spend hours in his garage. He did most of the maintenance himself, and if he had to take it to a mechanic, he'd stay with the car and not let it out of his sight."
Did Fernando ever drive it? He chuckles. "Only once, in 1962. He let me take it out of the garage, but I carried away the gates to the driveway as I reversed out. It was the only time he ever let anyone take the wheel."
Fernando's wife, Donha Maria, 61, says: "He swore that his son and grandsons would never eat sardines without bread like his family had to, and we never did." He would come home, she says, with tales of clients from all over Europe, children and grandchildren of former clients, who had come specially to Lisbon to see him.
For the moment, the car sits in the garage, although the family have no interest in keeping it now that its owner is gone. Tiago, 18, Macedo's great-grandson, admits he does not even know how to start it.
Stepping on to that wide, ribbed running board gives a sense of occasion even before you squeeze behind the wheel. The suspension on the wooden chassis is pretty stiff, and the front seat spans a built-in toolbox containing ancient smoothed spanners, the starting handle, the jack and a notched wooden dipstick for measuring the petrol level. Doubling over the steering wheel, I had to stretch way under the bonnet for the brass- handled brake.
The chrome is buffed to a silky sheen, the dashboard studded with well- worn knobs, and the massive black wings support Fernando's weight without a tremor. General Motors is interested in buying the car for their museum, he says, and the Lisbon city authorities have agreed to name a street after his father. That, and the film, should keep his memory alive.