96-98 were one style, 99-00 were 'cleaned up' a little.
different front bumpers/headlights/hood/grill/fenders, different trunk lid, rear bumper, and tail lights.
they changed up the interiors on 99-00's, primarly the hvac/radio consol.
some different colors were available on different years.
thats pretty much all I can think of. but its just about all cosmetics.