premise: In the nine months, GM Hughes net fell 6.6% to $486.6 million, or $1.48 a share, from $521 million, or $1.58 a share. Revenue rose 3.5% to $8.47 billion from $8.18 billion.
  At GMAC, net dropped 3.1% to $234.5 million from $241.9 million. The finance unit attributed the decline to higher borrowing costs compared with a year earlier. GMAC said its automotive financing and leasing business rose 35% in the U.S., largely because of dealer and customer incentives used to boost sales. GMAC profits are combined with earnings from the rest of GM's operations and attributed to the company's traditional common stock.
   Why did automotive financing and leasing rise in the U.S.?
hypothesis: dealer and customer incentives used to boost sales