There were a couple of options in the 2K+ era. From what I see in the shop manuals, in 2000 - 2002 there was an 8 speaker Bose system (RPO code U80). From 2003 - 2005 the option was the Premium 8 speaker Monsoon system (RPO code UZ
. What is interesting is that the 2002 sales brochure doesn't list the Bose system, it lists the Premium Monsoon system (which contradicts the shop manual).
Regardless, there was either the 6 speaker stereo with the amp built into the head unit or an uplevel system with 8 speakers and a separate amp.
The Bose or Monsoon 'uplevel' systems were only available in the top trim level (SSEi or GXP).
AM/FM/CD was standard in the SE and SLE but an AM/FM/CD/Cassette was an available option. In 2000 there was an AM/FM/Cassette option available. I'm not sure if this was also available in 2001 but was ultimately discontinued altogether at some point.
The AM/FM/CD/Cassette was standard in the SSEi or GXP.