May 2000 article in SAE’s Automotive Engineering Online describing Cadillac’s Imaj concept car, which features MR fluid-based semi-active primary suspension system
http://www.sae.org/automag/globalview_05-00/03.htm
http://service.gm.com/techlink/html_en/pdf/200201-en.pdf
http://www.cadillac.com/cadillacjsp/models/feature.jsp?model=srx&feature=ridecontrol