The 2006 Lexus GS 300 is available as a 4-door, 5-seat sedan. Starting at $43,150, the 2006 Lexus GS 300 RWD is powered by a 3.0L , 6 -cylinder engine mated to an automatic transmission that returns an EPA estimated 22-mpg in the city and 30-mpg on the highway. The top of the line 2006LexusGS 300AWD , priced at $ 45,100 , is powered by a 3.0L , 6 - cylinder engine mated to an automatic transmission that returns an EPA estimated 21-mpg in the city and 27-mpg on the highway.