A driver has received serious injuries after his car ploughed through a metal barrier off the first floor of a Westfield shopping centre car park in Adelaide's south, crashed to the ground and landed upside down.

Key points: The car landed upside down on the ground after crashing through a first-floor barrier and over stairs

The car landed upside down on the ground after crashing through a first-floor barrier and over stairs No-one on the ground was injured, but the driver was taken to hospital

No-one on the ground was injured, but the driver was taken to hospital Police suspect he may have hit the wrong pedal

Police said the 90-year-old male driver had been taken to hospital but miraculously no-one else had been injured.

The Ford Festiva crashed through the barrier on the Sturt Road side of the Westfield Marion car park, near the bus interchange, just before 9:00am.

"The car has actually come out from the car park, below the restaurants at the top, shot through a metal barrier, over the stairs, through the car park and actually almost made it all the way over to the bus stop on the other side of the bus interchange," Senior Constable Rebecca Stokes said.

"So it's travelled a fair distance. It's just a miracle that no-one on the ground was struck by this car as it was hurtling through the air."

Senior Constable Stokes said police were still investigating what led to the accident but suspected the driver may have hit the wrong pedal.

"It sounds like it's one of those car-parking mishaps where perhaps he's hit the wrong pedal, the accelerator and not the brake and the car's just shot through the barrier at the edge of the car park," she said.

He was taken by ambulance to the Flinders Medical Centre and is in a serious but stable condition, SA Health said.

The man's car was towed from the scene.

The shopping centre car park and bus interchange have since reopened.