"It was pretty clear what was happening - you could actually see the car kind of moving across the front of the shop. It was just a case of keeping myself and my customer out of the way."
Mikkelsen said the store was closed but customers could continue to shop online. Customers could also call the store if they needed help.
"We'll hope to be up and trading within a few days."
Bay Radiology Bay of Plenty regional manager Nicola Daisley said it was grateful no staff or customers were injured.
"Everyone on-site was understandably shaken and we commend everyone involved for their quick action," she said.
"Bay Radiology continues to operate out of the facility, with minimal disruption to our services."
Postie Papamoa manager Jessica Gregory said she initially thought the noise was "thunder".
She went outside and saw a car had gone into the Plum Organics store and went to see if everyone was okay.
"I noticed that there was an older lady in the car and that there was some gentleman (retired Tauranga fire officer Phillip Redmore) trying to help her so it wouldn't keep moving which I thought was a good idea.