 Design patents were filed in September 2004 in Japan, on 18 February 2005 in Europe, and 25 February 2005 at the United States Patent Office upon conclusion of development in early 2005.The second generation Lexus IS was the second debut of Lexus' new L-finesse design philosophy on a production vehicle, following the premiere of the 2006 Lexus GS performance sedan.The new IS design featured sleeker, coupé-like contours, a fastback profile, and a repeated arrowhead motif in the front fascia and side windows based on the Japanese concept of "kirikaeshi", referring to angular movements.