For the 2006 season, over 80% of the field began the season with a Dallara, a possible symptom of Panoz (manufacturer of the G-Force chassis)'s perceived lack of interest. This was around the time Panoz began delivering the DP01 chassis to the rival Champ Car series. From 2007 to 2011 all IndyCar teams used the Dallara IR-05 chassis, although a few teams entered a Panoz/G-Force chassis into the 2007 Indianapolis 500 singly. Some smaller teams continued to utilize the slightly older IR-03 designated chassis, particularly at Indianapolis, with update kits affixed to make it on equally competitive ground with the newer-assembled IR-05. Due to IndyCar IR-05 chassis and Honda Indy V8 engine development freeze for the reason of focusing on 2012 new car from the start of the 2009 season, Dallara did not build new IndyCar chassis until the 2011 season.