Model years
Yearly changes, upgrades usually took place at each "new" model year, outside of the factory bulletins or each teams development.
When more information is known, additions will be made
2009 GT3 RSR

Alex Job Racing 2002 GT3 RS
note the wider front fenders, revised front bumper, slightly different rear flares / rocker panels. Suspension changes, and front wheel offsets. Rear wing also changed it's profile, again for aerodynamics.
these cars also ran one piece BBS wheels throughout the season.