Automakers and dealers started July with larger stocks than normal after U.S. auto sales rose 2.4 percent in June.
Inventory on July 1 stood at 3.8 million light vehicles, up 57,000 from June 1 and more than a quarter million higher than a year earlier.
The industry had a 66-day supply based on how long stocks would last at the June selling rate. That was up seven from 59 days on June 1. It's also higher than the 59-day average for this date over the previous 24 years.
Days supply levels grew for every automaker during June with the exception of BMW of North America, which was unchanged, and Volvo Car USA, which fell 16 days to 50 on July 1.
Mitsubishi Motors' supply grew by 20 days to 102 days. Toyota Motor Sales, American Honda and Fiat Chrysler Automobiles also had double-digit gains.
Seven brands had more than a 100-day supply, led by Alfa Romeo. Alfa's stock is tiny nationally, but when a hundred-plus Alfa dealers sell just 36 cars in June, 400 cars in stock represent a 298-day supply. Then it's Fiat at 143 days, Ram and Buick each at 113, and Lincoln, Acura and Mitsubishi at just above 100.
Even capacity-constrained Subaru of America increased July 1 stocks to 27 days, up four from June 1.
The industry did manage to trim car inventory slightly despite the continuing downturn in car sales, suggesting production slowdowns are working. Since peaking March 1 at 1,576,900 units, car stocks declined by almost 95,000 or 6 percent to 1,482,100 units on July 1.