What are the symbolic meanings of Linda's washing and cars in Death of a Salesman?

In Death of a Salesman, there are a number of symbols. Two of these are Linda washing and the car.

Linda washing is representative of the everyday work that a housewife must perform.  She stays at home and keeps house, while her husband Willy goes on the road as a salesman.

Willy's life has not turned out as he would have wished, and his son's are a disappointment as well, though he never gives up hope for their eventual success.  However, Willy has had a least one adulterous affair while on the road--in Boston.  For this woman, Willy buys expensive silk stockings.  For his wife, however, he becomes angry and guilty when she is mending her own stockings; he does not buy new stockings for Linda.

I believe that Linda's washing also represents that part of Willie that is so conflicted. Linda keeps "the home fires burning" while he is away, and she loves and takes care of him even when he treats her badly.  He is not good to her: he talks over her when she speaks, yells at her and pushes her away emotionally.  In his heart, somewhere, I believe he does love her in a way, but her commitment to him, as well as his inability to provide for her in the way he should and his betrayal of her with at least one woman, make him feel lousy about himself, and he takes it out on her.  Her washing reminds him of the drudgery she happily carries out for his sake, and also reminds him of the poor husband he is in a variety of ways.  Regardless of all this, she never stops supporting or defending him.

The car (like the refrigerator) represents obstacles in Willy's path that make him feel frustrated and angry.  The car is always breaking down.  While Willy feels cheated (believing the car and refrigerator belts are made to purposely last only so long), he also resents that to keep the car functional, he must continue to invest their much needed finances into things that regularly eat away at the little money they have.  The car also represents a powerless Willy feels by what goes on in the world around him. (It is important to note that the car also endd up being the means by which Willy takes his own life.)

The multiple symbols in the story support the plot's development, while drawing attention to Willy's many internal and external conflicts.