In a stifling hot courtroom on a recent afternoon, Los Angeles County, Calif., Superior Court Judge Anthony Mohr deliberated the proper jurisdiction for billions of dollars in claims filed by the insurers of Toyota owners who alleged their vehicles suddenly accelerated out of control.

On one hand, Mohr reasoned, it would make sense to litigate the insurers’ claims alongside a raft of nearly 100 additional lawsuits against Toyota Motor Corp. in a coordinated proceeding in California state court. But he acknowledged that the vast majority of the insurance claims involved accidents in 31 states other than California,and that those states have their own grounds for exercising jurisdiction.