The 2004 Porsche 911 model saw the addition of the C4S and Turbo trims alongside of the GT3 and the 40th Anniversary model. Various upgrades were made to different models, in-line with basic shuffling of trims. 2005 marked the year for big changes. More powerful engines were introduced, a new transmission was unveiled, rack-and-pinion steering was added as well as adjustable suspension systems, and a new passenger compartment was incorporated. In 2006, the 911 offered an optional all-wheel-drive system as well as the desirable Carrera power kit, which boosted horsepower to 381.
New 19 wheels were introduced, and a tire-pressure monitoring system debuted with an automatic airbag cut-off switch for passengers. 2007 saw the return of the 911 Turbo and the GT3 sports models, offering robust horsepower and sports-tuned handling. In 2008, the GT2 model returned, boasting 530 horses under the hood. A laundry list of updates was in store for 2009, with new front fascias, direct-injection engines, larger and more powerful brakes, and an all-new touchscreen console and center stack. The most notable changes for 2010 were the return of the GT3 and GT3 RS trim levels.
Major trim shuffling in 2011 saw updates to the GTS, Turbo S, GT2 RS, GT3 RS and limited-edition GT3 RS 4.0 trims, with some trims making their debut. A redesigned 911 was unveiled for 2012, sporting a longer, wider frame and a superior engine. The 911 crossed through 2013-2014 relatively unchanged, with exception to tweaking of the trim levels.