probaly public domauin as they do not intend to be any thing other that the theorectiacl image of a possible future product. I woul check with a legal dept. if you wanted to use these in a advertising situation or a image done for compensation. Warhol used Campbell soup without undue legal problems.
quote from 
http://www.artrepublic.com/Posters/biography/biography.asp?artist=Warhol&name=Andy

In 1960 Warhol began to replicate a range of mass-produced images, beginning with newspaper advertisements and comic strips before turning to packaging, dollar bills and more. He is probably the most famous member of the Pop Art movement. Virtually any image that was in the public domain was a prime target for the Warhol treatment. In 1962 he had his first one-man show at the Ferus Gallery in Los Angeles and in the same year exhibited at the Stable Gallery in New York. This was the year of '32 Campbell's Soup Cans' (1961-1962). Soon after his sculptures of Brillo soap pad boxes, Coca-Cola bottles and replications of popular icons such as Elvis Presley, Elizabeth Taylor and most famously Marilyn Monroe were to appear and secure his reputation. The silk-screen process he favoured allowed for infinite replication, and he was opposed to the concept of a work of art as a piece of craftsmanship executed purely for the connoisseur; in Warhol's own words, "I want everybody to think alike. I think everybody should be a machine." 
I should point out that I an by no means an attorney or claim to have anything other than an opinion here.