Historical clue formulations

• Green machine — 2022-09-13
• Green vehicle — 2021-09-12
• Green machine — 2014-10-04
• Green traffic sight? — 2013-06-22
• Green jam ingredient? — 2013-01-12
• Green wheels — 2012-12-08
• Green vehicle — 2012-06-24
• Prius, e.g. — 2010-08-24
• Green vehicle — 2008-01-26
• Prius, e.g. — 2006-05-03