Cats were changed across the years during which they were manufactured.

This three-year-old article mentions SOME of the items which make the five Cat model year cars different:

http://www.carpages.ca/go/preowned/1997__2001_cadillac_catera.aspx

I thought I should add... thats good info as well but here is some more..


http://media.gm.com/division/cadillac/products/00cadillac/catera/00press_release.htm