Volkswagen and government regulators must present a detailed plan within a month on getting nearly 600,000 diesel cars to comply with clean air laws or risk the possibility of a trial this summer over an emissions cheating scandal, a federal judge said Thursday, according to AP. Senior U.S. District Court Judge Charles Breyer said he wants to know the timing of the fix and any planned payments to owners, among other details, by April 21. "I would hope by the 21st that as many outstanding issues as possible will be wrapped up, but at least the issues of what is to be done with these cars must be resolved by that date," he said. Volkswagen acknowledged in September that it intentionally defeated emissions tests and put dirty vehicles on the road. The cheating allowed cars to pass laboratory emissions tests while spewing harmful nitrogen oxide at up to 40 times the level allowed when operating on real roads. The Department of Justice sued Volkswagen on behalf of the U.S. Environmental Protection Agency. The company also is facing lawsuits from angry car owners, who are demanding Volkswagen buy the vehicles back. Those cases are both before Breyer.