A total of 34 cars worth an estimated £300,000 were damaged when a floor collapsed at an Audi dealership - almost twice as many as first thought.
It was initially feared that at least 20 cars were involved when a 200m by 100m section of the upper floor gave way.
But Jardine Motors Group which runs the showroom in Milton Keynes, Bucks now says a total of 34 - including six belonging to customers and 28 others - were smashed.
The company has not yet revealed the cost of the damage to the building and cars or the cause of the collapse on June 1.
Commercial director Jason Cranswick said the cost of the damage was still being assessed by insurers.
Staff spotted the danger and hit the firm alarm which triggered an evacuation around 20 minutes before the dramatic collapse.
Ian Wilson, from Bucks & Milton Keynes Fire and Rescue Service, said staff had a “lucky escape and no one was injured.
Customers whose cars were damaged were given courtesy vehicles and permanent replacements will be arranged for them, the company said.
The showroom was specially designed and constructed in 2014 to include a car park above the workshop area, accessible by a ramp at the rear of the building.
After the accident the Jardine Group said the first floor load was “significantly within design limits”.
The workshop has been relocated to another part of Milton Keynes for the next six months.
Milton Keynes Council said building control inspectors investigated the incident, but the Jardine is now taking the lead.