Maybe you better iron it also!

From The Encyclopedia of Jewish Humor by Henry D. Spalding.

Teen-age Marvin had just bought a battered old car for twenty-five dollars. It was in such bad condition that even the auto wreckers had refused to buy it. Nevertheless, Marvin, who never owned a car before, was quite proud of his new possession. On the first day, he insisted on washing the crumpled, dented, rusted jalopy.

His father, who was watching the laundry operation with a caustic smile, finally commented:

"Marvin, into your business I want you to know I'm not sticking my nose, but after you finish washing that thing, maybe you better iron it also!"