These will be Specific for the US. There were some differences in colors available throughout the world like the US getting Pearl White while others got Glacier White
For more specific year to year changes see Year by Year Changes
In 2005 We didnt get the official documents. Ill try to track them down for posterity.
There were just a couple changes. Lightening Yellow was dropped and Pearl White added. Switch-Blade Key was introduced.
Pricing was as follows
MSRP for the 2005 Mazda RX-8
$25,375 - 4-speed Sport Automatic Transmission
$26,875 - 6-speed Manual Transmission.
The MSRP's for the Packages and Options :
$4,950 - AT Grand Touring Package
$3,775 - AT Touring Package
$2,000 - AT Sport Package
$4,250 - MT Grand Touring Package
$2,975 - MT Touring Package
$1,300 - MT Sport Package
$2,000 - Navigation System
$200 - Pearl Paint Charge