General Motors Corp. v. Keystone Automotive Industries Inc.
Infringement defendant who sells component part for plaintiff’s end product can use plaintiff’s trademark to show that its product is component part, provided defendant otherwise makes clear to prospective purchasers that part was not made by plaintiff; in present case, defendants’ sales of their replacement grilles for plaintiff’s vehicles, embedded with plaintiff’s “bow tie” and “GMC” designs, are not likely to cause either point-of-sale confusion or “downstream” confusion.