puffer
n.— «The police call them “puffers,” most likely because the little clouds of exhaust they exude during the cold, wintry months resemble puffs of smoke. The police term refers to cars left running while owners wipe off snow, scrape frost and head back inside for one last cup of coffee before heading to work.» —“Puff and it’s gone: running cars equal trouble” by Amanda C. Sutterer Broomfield Enterprise (Colo.) Jan. 19, 2005. (source: Double-Tongued Dictionary)