George V. Rael’s “arm protective garment,” patented in 1994, addresses a unique need:

The ordinary motorist may wish to particularly shield his hand and arm from sunburn while driving along on his or her usual daily route, or on longer vacation drives. Air conditioning is great, but driving on a lovely day with one’s arm resting on the ledge of an open car window is found enjoyable by many drivers. The driver’s enjoyment, however, can be shattered if the drive results in a severe sunburn to the hand or arm.

The answer is a combination sleeve and mitten to protect the left arm from the sun’s rays. Presumably there’s an alternate version for vehicles with right-hand drive.