Cheers to Hyundai for their attention to air quality issues. Their 2005 Sonata GLS features "in-cabin air filtration".
Here's an excerpt from the April 6th Korean Herald:
"Hyundai Motor Co. will begin domestic sales of its upgraded 2005 Sonata midsize automobile today (in five versions).... Among them is the new 2.4 liter 'Elegance Special' model targeting women customers with sleeker design and more convenience features such as an electronic air-purifier."
The company's American website also lists air filtration as part of the specs on the GLS.