When I worked for Mercedes the owners manual came with a coupon for a free one. I reember convincing a newbie that if you removed the radiator cam, collapsed the upper rad hose and put the cap back on he could install the heater without spilling. 
He tried it from underneath the car. Hillarity ensued. 
I used a block heater on a garage-less Prelude in Wisconsin for many years. It really helped on the coldest mornings. I'd say it would be money well spent.
I had one of the freeze plug style heater in my diesel pickup. GM factory in the 6.2 diesel that was in the truck.
While it wasn't necessary when the glow plugs were working well, it did make starting easier.
I also had heat ( warm not hot) almost immediately. I would use a timer to turn it on a couple hours before I had to leave. I would start the truck, letting it idle while plugged in, and scrape the windows before unplugging the heater.
I'd love to have one of those in our current vehicles, but I don't like the idea of adding it to a vehicle under warranty. I should check and see if Kia or Hyundai offer them as a factory accessory.
You'll need to log in to post.
