"Buggatti" was Mme Duncan's pet name for her lover, who was driving the Amilcar, which was likely a Racer, and anything but pedestrian. There were rather boring Amilcar's produced in the 30's, but the 20's models were another matter entirely, as was the later Pegase, which must be seen to be believed.
Archer
Too late to ask, but I wonder if Mme Duncan was referring to her friend's prowess with his single piston sports model.
Rob C