[Huz-Z]

I typically warm up my car during winter. Here's why.

Its typically quite cold in winter here. And it may have snowed overnight, meaning that there is snow and ice on all the glass surfaces. If I get in, start, and drive away from cold, I will absolutely find that the windshield cleaner fluid will freeze on the windshield, even though its rated for -45C and my X5 has a heated sprayer. Also, the back glass is likely still mostly or partially fogged over, obscuring visibility behind. Similarly, the windshield itself, side mirrors and side windows are likely to still have some ice outside and fogging inside - even if I have cleared them carefully with a good snow brush / scraper. Warming up the vehicle allows the engine to heat to the point where the HVAC system can blow air that is warm enough to warm the windshield which keeps windshield cleaner fluid from freezing, and to fully defog the windshield and side glasses. And for the rear defogger / mirror heating to properly clear those surfaces.

I also take time to clear the snow off the roof; my snow brush telescopes so I can reach across the top of the X5. I've seen other SUV drivers who didn't do that stop suddenly, only to have the blanket of snow on the roof form an avalanche down over the windshield, completely blinding the (idiot) driver.

As I've noted, I do see guys who don't bother to do any of this. In my view they are taking a big risk driving while trying to see through a partially obscured windshield and side windows. I don't want to be that guy. Should they be involved in an accident, they may incur additional legal liabilities if the other party can show that the other guy's windows were not cleared fully. Its also a good idea to take the time to brush off your headlights and brake lights at the rear, for obvious reasons.

So. Warming up the car in winter is a safety measure that ensures that the driver has optimal visibility to drive. You also end up performing a full external inspection of the vehicle before driving, in the process. Safety first.