Most of us spend far greater time attending to the exteriors of our automobiles that we do on their internal workings. We scrub them clean and polish them to lusterous elegance. Each year Americans spend millions on special detergents for cleaning whitewalls and special polishes for chrome and vinyl. Ah, cosmetics.

Meanwhile, the sparkplugs and oil haven't been checked or changed in 25,000 miles, nor have the radiator, battery or wiper fluid levels. We don't do many of the really important things to extend the lives of our cars, but they sure look good.

It's always a surprise when the old bomb breaks down . . . and a humiliation when the cause of the break-down is traced to a non-existent maintenance program.

Unfortunately, most of us treat our bodies in the same negligent manner. While we'll spend thousands on clothes, wigs and deodorant, it's an unhealthy fact most of us don't even made a minimal effort to balance our diets or to include substances such as bran, which has been proven time and again as an effective gastrointestinal tract cleanser.

Maybe bran is misunderstood: "Bran, yeah, I guees I ought to eat some, but what is it, what does it do . . . and when should I eat it?"

Bran is the partly ground husk of wheat of other grains. While it has minimal nutritional value, bran is an excellent source of roughage. Roughage is indigestible and can be viewed as an extremely efficient army of inorganic G-I tract cleaners.

As soon as you've finished attending to the oil, sparkplugs, tires, radiator, battery and windshield wiper fluid, head to the health food section of the store and buy the ingredients for these delicious Bran Dandies, a sure-fire recipe perfected over many years. Your insides, regardless of your age group will soon let you know how grateful they are if you start eating Dandies. BRAN DANDIES (40 to 50) 3 cups raw, unprocessed wheat bran 1 cup unbleached flour 1/2 cup wheat germ 1 teaspoon baking soda 1/4 teaspoon salt 1 cup plain, lowfat yogurt 1/2 cup minus 2 tablespoons molasses 1/2 cup milk 1/2 cup raisins 1/4 cup minus 1 tablespoon peanut oil 2 tablespoons honey 1 tablespoon peanut butter

Mix the dry ingredients together, leaving a crater in the middle. Add the liquid ingredients and mix together briefly until a thick, evenly moist consistency is achieved. Add the raisins and 2 lightly beaten egg whites and stir 10 strokes or so until the raisins are evenly distributed.

Drop balls of dough slightly smaller than Ping Pong balls on a greased cookie sheet. Flatten the tops somewhat with a thumb and bake for 20 to 25 minutes in a preheated 350-degree oven.

Bran Dandies store best in a plastic bag kept in the refrigerator.