According to the autopsy, Lorena Vezzosi had been stabbed to death before being placed in the vehicle in her underwear.
The victim was killed by her ex, Stefano Del Re, doctors said.
The pair, although separated, lived in the same mountain town near Rimini, Santarcangelo di Romagna, and had two children aged 14 and 17.
Neighbours and friends have told police they often argued about their children, while De Re was reportedly obsessed with the fact that Vezzosi had found a new partner.
Del Re drowned after driving the car into the Po and committing suicide.
ANSA
