I could be wrong but I think all Lexus' are rwd.

or at least the IS series
IS 250 - 2.5 L 4GR-FSE V6, 204 hp (153 kW), rear wheel drive
IS 250 AWD - 2.5 L 4GR-FSE V6 with all wheel drive (with front:rear torque split of 50:50 to 30:70), 204 hp (153 kW)
IS 350 - 3.5 L 2GR-FSE V6, 306 hp (228 kW), rear wheel drive
IS F - 5.0 L 2UR-GSE V8, 417 hp ( 311 kW), rear wheel drive