A 23-year-old woman remains in hospital after an Audi hit a hedge and flipped over before landing on its roof in Stoke Mandeville.
At about 12.40am on Sunday morning a black Audi A3 was being driven along Lower Road when it left the road.
The woman, who was a front seat passenger suffered fractures to her back and ribs and a suspected punctured lung.
She is currently being treated at Stoke Mandeville Hospital.
Investigating officer PC Steve Leathersich said: “I would appeal to anyone who saw a black Audi A3 being driven in the area prior to the collision or the collision itself to contact police via 101 quoting reference 7269.”
Alternatively, contact Crimestoppers anonymously on 0800 555 111.