In a statement released on 25 March, ARB Executive Officer James N. Goldstene said:

Following the June 2009 Board adoption of the cool cars regulation, stakeholders raised several new issues involving performance of electronic devices as they may affect public safety. After listening to this input and accounting for the legal deadline to finalize the rule, today we are announcing that the AB32 “cool cars” rulemaking will cease. Instead, the Board will pursue a performance-based approach as part of its vehicle climate change program to reduce CO₂ from air conditioning and provide cooler car interiors for California motorists.

The cool cars regulation was early action item under AB 32 and adopted by the Air Resources Board (ARB) in June 2009. When fully implemented, it would have required a 60% reduction in heat absorption through vehicle windows.

Cool Cars specified that vehicle windows must meet certain standards for heat transmission. Based on these requirements, ARB expected reflective glazing to be installed on windshields in 2012 and on all windows in 2016, unless automobile manufacturers decided to use an alternate performance option for 2016 and beyond.

However, reflective windows are known to attenuate electromagnetic waves, and in preparing the rule, ARB staff had researched what methods could be used to mitigate signal attenuation. Staff determined that a portion of the reflective material could be removed in order to facilitate operation of electronic devices. Concerns were still raised that devices such as global positioning system (GPS) monitoring ankle bracelets, cell phones, and GPS navigation devices will not operate as intended in vehicles with reflective glazing.