2021 GMC Sierra HD pickupGMU.S. auto sales for General Motors declined 11.8% in 2020 but showed strong signs of a recovery in the fourth quarter, the company said Tuesday.GM’s domestic sales rose 4.8% during the last three months of last year compared with the same period in 2019. Retail sales for the entire auto industry returned to pre-pandemic levels in the fourth quarter, the company said. Commercial fleet customers also started to return toward the end of the year, it said. GM’s strong fourth quarter is likely a good sign for the auto industry overall. The majority of automakers are scheduled to report their U.S. sales on Tuesday. Domestic vehicle sales in 2020 were expected to be off by at least 15% compared with 2019.