Gran Turismo 5: Spec 2.0 is a major update to Gran Turismo 5 that added new content, in-game adjustments and bug fixes. The update contained mostly community-suggested ideas. Shortly after the update, four  DLC packs were released.
Patch notes for Spec 2.0  Edit
Simplified interior views added to all Standard cars.
User control of the weather change feature.
Settings sheet that allows you to save multiple car settings.
New Spec 2.0 opening movie (no longer available after the server shutdown as it was part of the now-defunct Gran Turismo TV)
Improved UI usability and response
Expanded online lounge features (narrowing down cars types, shuffle races...)
Expanded Photo Travel features (you can now take photos with your avatar)
Added NASCAR Pit Scene stage to Photo Travel
Added 11 new 2011 NASCAR models
Added the Nissan GT-R N24 Schulze Motorsport '11 (the car in which Kazunori Yamauchi contested the Nurburgring 2011 24 Hours)
The 2011 Jeff Gordon ♯24 Drive to End Hunger CHEVROLET IMPALA '11 replaces the 2010 Jeff Gordon ♯24 DuPont CHEVROLET IMPALA '10 for the Jeff Gordon NASCAR School Special Event
Improved physics and Artificial Intelligence (AI)
Support for the Logitech G25/G27 steering wheel
A huge majority of races begin with a rolling start
The Gran Turismo 5 XL Edition and Gran Turismo 5: Academy Edition both include the Spec 2.0 Update already installed.
↑ 1.0 1.1