In the first incident at around 7pm on Tuesday March 14 a stone was thrown through the window of a vehicle travelling along the Marroway - but no one was injured.
In the second incident between around 9.30pm and 9.45pm on Thursday March 16, the victim, a 66-year-old woman was travelling in a car along the Marroway when a stone was thrown.
The stone smashed through the window and hit the victim in the face but she was not injured.
PC Joanna Smith of the neighbourhood policing team based at Wendover police station said: “I would like to appeal for any witnesses to this incident to contact me.
“If you have any information please contact me or PC Thomas Piercy via the Thames Valley Police enquiry centre 101.”