Large car manufacturers in the US are required to support their cars that they give warranties for by the the federal Magnuson-Moss Warranty Act, which are 10 or 12 years long by this point.

The contracts underlying the support for consumer automotive commonly run around 10 years. After that it is best effort and unofficial support by other companies if there is enough money to be made by offering it.

Cars don't really need an online component in order to continue working. Some manufacturers have tried to force some features into online components, but the cars continue to work without it once they turn it off.