Lexus GS 450h enters its third model year as still the only hybrid-powered luxury sport sedan in its segment. With its advanced technology, high performance and indulgent luxury, the rear-wheel-drive 2008 GS 450h is the premium model in the GS series.The Lexus GS 450h is not a car, it's a decadent lifestyle. I had it wrong, Lexus drivers aren't bad at all. They're spoiled in a way we all want to be.The GS 450h begins at $56,400 and goes up from there. The hybrid powertrain also enhances performance, but doesn't seem to help much at the pump. I averaged 24 miles per gallon in mixed driving, which is on par with the EPA rating of 22 mpg in the city and 24 mpg on the highway. Naturally, this thoroughbred requires premium fuel. 