Where I live, it’s a joke to let you car idle so it will be easier to ”scape” your windshield. You either have frost or ice on the windshield ( or snow which comes off easy ). For frost , buy the best windshield fluid ( harder on blades though ), start the car and turn on the wipers ( spray ) and that’s it. No scraping required or waiting. If it’s more than frost and its ice, your car won’t be able to melt it at idle unless it sits there an awefully long time and even then forget in many situations here. No way I am going out to start a car and go back in the house and wait.
People starting their cars waiting for them to warm up to remove ice..... reminds me of work. I would often land late from a flight and cars would be often covered in ice ( freezing rain or snow that had tuned into ice ). I would always park my car beside the outside washroom ( sink inside ) and carry an empty windshield washer container so I could fill it up with hot water and then pour it on the front windshield. I would start my car and be gone within minutes ( unless lots of snow on roof of Coarse ) while every other driver would be wasting time waiting for their cars to warm up ( it would never get warm enough ...ice over air intake too ) and out scraping away. Many even ( smart phone auto start app ) started their cars just after landing and would still be scraping when I left. I have never cracked the windshield doing that.
I don’t drive with snow on the roof of my car.
