I had the dealer install an engine block heater I bought two years ago 06 civic Engine Block Heater
I also stuffed the upper grille with 3/4" pipe isolation and got about 5 mpg more last winter. But the commute is only about
7 miles which barely gives the car enough time to warm up much less add to the average mpg.
Next year I'm planning to add insulation in the trunk and a heater plus a heater in the back seat in an attempt to keep the pack warm.
Since the engine block heater only heats the coolant I'm also looking into a oil pan heater.
I want to wire them all up to one plug and mount it something like the plugins use.
It will be interesting to see how efficient I can make all those heater work together. Hopefully, I'll be able to switch on the heaters an hour or two before
I go, than just start it up and drive. I probably wouldn't get it all setup by next winter, but that is what I'm working towards.