In early April, a federal judge heard from plaintiffs who wanted General Motors to tell owners of 2.59 million vehicles affected by the "Switchgate" recall to park those cars until they were fully repaired. Several days later, the judge ruled that GM didn't need to do any such thing.
In her decision, Judge Nelva Gonzales Ramos said that federal regulators were better positioned to manage the recall and that the courts should stay out of the fray. (Presumably, judges like Ramos will have plenty of work on their plates when it comes to lawsuits over wrongful death, loss of resale value, and many other matters.)
Subsequently, Senators Richard Blumenthal (D-CT) and Ed Markey (D-MA) appealed directly to the top federal regulator in this case, Transportation Secretary Anthony Foxx, asking him to issue a "park it" order. According to Bloomberg, however, Foxx has declined the senators' request.
Foxx's response made it clear that he believes GM has given sufficient safety advice to owners of recalled cars, asking them to drive with only the ignition key in place until the faulty switches are fixed. In his letter to Blumenthal and Markey, Foxx stated that "[The National Highway Traffic Safety Administration] is satisfied that for now, until the permanent remedy is applied, the safety risk posed by the defect in affected vehicles is sufficiently mitigated."
Blumenthal and Markey issued a joint statement voicing their displeasure with Foxx's decision, but at the moment, it doesn't appear that they intend to pursue further action. Now that a federal judge and the head of the DOT have weighed in, GM and NHTSA will likely be left to handle the recall as they see fit.