TBH, it's one of the reasons I've kept my car for so long (only normally keep them for 3 years - but I've had the Golf now for 5 !). This morning for instance, outside temperature at 7.15am where I live, -9.5°C. Started the car, and within 3-5 minutes of driving off, outside temp -9°, butt cheek and back temperature +25°C, nice and toasty.
Also, as mine is a soot chucker, the car also has the electric PET heater installed (as all the diesels do), so that means not only was the seat nice and warm, but within a couple of minutes of starting, I had piping hot air coming out of the air vents. Nice.
