I never let my vehicles 'warm up'. I let it run, while I brush or scrape the windows. Most of the time, once the idle drops from high to low...I go. I wear a jacket, gloves and a hat. I take it easy until, I see the temp gauge move(about a mile/5 min). I have a neighbor, who remote starts his truck, year round. I hear it annoyingly, running constantly. He puts 'hours' of run time, without moving. He probably wastes $10-$20 a week in gas. What about wear and tear on the battery and starter? My father's Highlander shuts off and has to be 're-started', before you go. Carbon build up, from extended idling is bad also. Its only a matter of time, before the EPA goes after manufactures, for the pollution this must create. They put all this 'emission' stuff on cars, but enable it to idle for 20 mins, with no one in it.