At 8pm on Friday evening (20/9), the victim was a passenger in a car in Chaffron Way near the roundabout opposite Waitrose in Oakgrove.
She and the offender were driving home when the offender punched the victim repeatedly and pulled the car over on Chaffron Way.
He then pushed the victim out of the slow-moving car before driving off.
The victim, a woman aged in her thirties, sustained a black eye and reddening to the back of her head near to the ear.
The vehicle she was a passenger in was a grey Mercedes A-Class, 2013 model.
A 45-year-old man from Walnut Tree, Milton Keynes, has been arrested on suspicion of assault occasioning actual bodily harm and has been bailed until 22 December while investigations continue.
Investigating officer PC Codrut Lungulescu, based at Milton Keynes police station, said: “I am appealing to anybody who was in the area of Chaffron Way in Oakgrove on Friday evening who may have witnessed this incident to please get in touch with Thames Valley Police.
“I’d also like to hear from anyone who may have dash-cam footage which could have captured the incident.
“Please check this, and contact us if it has picked up anything that may assist this investigation.
“You can make a report online or by calling 101, quoting reference 43240453848 or call the independent charity Crimestoppers anonymously on 0800 555 111.”
