The accident took place in the city’s inner west just before 7.30am on Sunday.
Two 19-year-olds allegedly tried to steal a woman’s scooter, before driving away.
They allegedly rammed another woman’s car as she tried to stop the escape.
“My scooter was stolen, we happened to find it,” the alleged victim said.
The two men made it a kilometre down the road before crashing.
The impact was so severe the car was “almost cut in half”, police said.
The two men were treated at the scene before being taken to Royal Adelaide Hospital.
The driver was in a serious condition with facial injuries, however, neither of the men were believed to have sustained life-threatening wounds.
The investigation is continuing.