My Observations.
The regular EA and ES are often mixed up and people pick from either side. They arent very segregated.
Regular EA:
Chevy Impala
Dodge Charger
Dodge Avenger
Dodge Magnum
Chevy Malibu
...other junk
ES usually:
Chevy Impala
Dodge Charger
...other junk
Somewhat rare:
behold the elusive Impala SS (dont get in front of me if I am heading for it!)
Rare:
Grand Prix G6 / GXP