As overall auto sales levels weaken amid concerns about the economy, new terrorist threats and the faltering stock market, car makers are starting to offer discounts on even their highly profitable luxury models, including Porsches, Jaguars and Land Rovers, according to a recent Wall Street Journal article. There are also new lease discounts available on Saabs and Volvos. Luxury car sales -- which account for about 17.6 percent of the U.S. vehicle market -- have been holding up relatively well until recently. But May showed major signs of softening.