Im thinking of buying a WRX. What are the differences between years?

Exactly like the subject says. What were the changes, if any, between different year WRX's?
Thanks
Jim

Which particular years in what country.

Most of the changes on the 2002 through 2004 WRX's in the USA were cosmetic.

In japan how ever their almost endless, changes were made every 6mnths, and that dosnt include all the special models, from RA and RS spec, down to diffent STi models.

In other overseas markets the changes are much smaller, generaly just minnor improvments to the engine to match the cars increasing weight with each new model.


But generaly the later the car the better it will be, as a subaru never stopped doing development work with each new generation.
The only exception is a limited run of Australian models. The inablity to get high octane fuel in some parts of Ausie caused several WRXs to wreck engines through detonation. Subaru was forced to replace these engines under warrenty, as they had failed to specify a minimum octane fuel requirement when the cars were sold new. As a result there is one generation of WRX sold new in Ausie with less hp than the rest of the world, thanks to lower boost levels, and much milder ignition timeing.
Its also why australian magazines give accleration times for the WRX that are noticable slower than everyone elses.

Thanks guys but I am looking for US models. I was just wondering if there were any changes between the years of when the WRX was first made till now. Is there one year that is better than others that I should be looking for? One year that has been dyno proven to have more HP than the rest?

Jim