Hi, welcome to the forum, 2000 was a very good year for Boxsters (notice mine is a 2000). If you have a chance, take a test drive in a 2005 boxster S and see how it feels compared to your car. The newer car will be a little heavier, but you will still get a sense of the difference in power. You are right in that it is difficult to easily and cheaply get more power out of these engines with simple intake, exhaust and ECU mods. How do you find the drive and road handleing compared to some of the other cars you have owned?
Ed