OK, this seems like a no-brainer. As GM and Ford have gradually pulled back from the low-margin fleet sales market, import fleet sales have surged. After all, somebody has to keep the rental car lots filled. It's mostly been the mainline Asian automakers that have stepped in to fill the void. Toyota, Nissan, Mazda and Kia have all increased their corporate sales of cars and trucks, but they still remain bit players overall. About 11 percent of U.S. import brand sales are to fleets so far this year. That is up from just 8% last year. In comparison, the domestics sell 31 percent of their overall production to corporate customers. Although some fleet sales can be quite lucrative, the vast majority of rental car sales are end-of-year surplus that is heavily discounted to move.

[Source: Automotive News - sub. req.]