The mysterious workings of your car's systems -- and how to maintain them -- are covered in classes on basic automotive awareness. Among them:

Open University, 3333 Connecticut Ave. NW, Washington, D.C 20008 (966-9606). Auto Maintenance: a single two-hour session, next one in January, $9.

Montgomery College, Community Services (279-5188). Automotive Awareness, 10/2 1/2-hour sessions, $65; Automotive Driveway Mechanics, 7/3-hour sessions, $80; Engine Tune-Up, 7/3-hour sessions, $85. Begin in January.

Montgomery County Adult Education (942-8304). Basic Automotive Maintenance, 8/2-hour sessions, $20; Tune Up Your Car, 3/2-hour sessions, $12. Begin the week of Nov. 30, at county high schools. Catalogs for out-of-state residents available at Montgomery County libraries.

Mt. Vernon College, 2100 Foxhall Rd., Washington, D.C. (331-3539). Basic Auto Mechanics, 6/2-hour sessions, $45; Intermediate Auto Mechanics, 6/3-hour sessions, $65. Begin in March.

Northern Virgina Community College, Alexandria Campus, 3001 N. Beauregard St. (323-4240). Weekend Clinic: Bring your car and do your own tune-up, this Saturday and Sunday, 9 a.m.-4 p.m., $35. (Offered again in January.)

Prince George's Community College, Community Services, 30l Largo Rd., Largo (322-0875). Automotive Maintenance I and II, 8/3-hour sessions, $40 for each course, begins in February. Call for the catalog.

Seidel Chevrolet, 7610 Central Ave., Landover (350-4100, Hans Funk). Basic Automotive Maintenance and Advanced Automotive Maintenance, six 1 1/2-hour sessions, free. Begins week of Dec. 17.