Patricia went to the hospital on Sunday to see the damage to the vehicle.
"I walked around the car park and was just blown away. There was smashed glass everywhere."
The vehicle had to be towed, and Patricia's insurance company is now deciding whether the car can be fixed or will be written off.
She said it's the second time the car has been damaged while parked at the hospital.
"Security at the hospital is crap - they just don't seem to be watching. The amount of damage that was done was so much that surely someone must have heard something."
Patricia said she knew staff were concerned about security in the hospital car parks. She would like to see increased lighting and security cameras in the car parks.
Whanganui District Health Board spokesman Brian Walden said he understands the break-ins and thefts were upsetting for staff, especially those who own the damaged and stolen cars.
He said anyone who has a car stolen or damaged should report the incident to the police, who will contact the DHB for more information.
Mr Walden said a security guard was available at the hospital every night of the week, with two on at weekends.
"The security guards can be contacted through our reception desk staff who are based in the emergency department at night.
"We have always told our staff that they are able to ask the night-time security guard to escort them to their cars at the end of their shifts," he said.
"All carparks at the front of the hospital campus are well lit. We do have security cameras in the carparks but coverage is limited."
Mr Walden said the WDHB will look at whether its camera coverage needs to be increased.
He said the duty manager on duty last weekend approved taxi vouchers for staff whose car were stolen or disabled.