New York CNN  —  CDK Global, the retail software provider behind the massive auto dealer outage, says it doesn’t believe its systems will be back online before June 30, a major blow to car buyers and sellers who have been struggling to complete auto sales during peak car buying season. A systems outage caused by a cybersecurity incident has paralyzed nearly 15,000 car dealerships across North America since last Wednesday. In an automated voice message to clients, CDK said it is making “significant progress” in restoring its core application. “We do feel it’s important to share that we do not believe that we will be able to get all dealers live prior to June 30,” the message said. The company also urged dealerships to make alternate plans for the month-end financial reports. Auto dealerships use CDK’s software to manage everything from scheduling to records, said Saturday it has begun restoring its software. But it has suggested several times that a fix is in order, only to then say that its systems would remain out of commission for a while longer. Meanwhile, some dealers have been fulfilling orders with pen and paper. Other services, such as state inspections, repairs and parts deliveries, have come to a standstill in some parts of the country. CDK has said it is working to investigate the shutdown after two cyber incidents brought down its systems. The company has not confirmed who was behind the incidents. Bloomberg previously reported the company was negotiating with an Eastern European-based hacker group demanding tens of millions of dollars in ransom to end the outage.