The furry local sparked a five-car pile-up while crossing the road at Crafers West, bringing this morning's peak-hour traffic to a stand-still.
"I thought okay, if we don't catch this koala now and the traffic starts moving, they will stop suddenly and there will be another pile-up of cars," Nadia said as she found herself staring at the cause of the chaos.
"I saw to my right to the front there was a little cute koala running towards me."
Nadia said she was able to catch the koala with the help of other drivers and put it in her boot until animal rescue teams arrived.
"I grabbed my jacket out of the back seat and I went to the koala on this side like a toreador would do to a bull," Nadia said.
But the cheeky koala decided its adventures weren't over as it took to the wheel.
"It was poking its nose through the headrest and I thought, okay that's too close for comfort - I'd better get out and you have the car," she said.
Surprise culprit after mysterious case of cat trap tampering in WA
The koala stayed calm until animal rescuers arrived and returned it to the wild, although not before leaving its mark on Nadia's car - a deep scratch clawed into the dash.
No animals or people were injured in the crash.
