According to the Federal Register, the law will now take effect on September 1st, 2020, pushed back from late 2019. All EVs and hybrids produced on after the effective date must have a minimum sound. Starting on September 1st, 2019, 50 percent of hybrid and electric vehicles produced by any manufacturer must meet the standard.

The National Highway Traffic Safety Administration (NHTSA) and the Department of Transportation implemented the delay (again) in response to carmakers such as Honda and General Motors. Apparently, there are "several reasons related to vehicle design, development, and manufacturing that will make it very difficult if not impossible for manufacturers to meet the final rule's compliance phase-in schedule," according to the NHTSA's report.