I think a stick-on silicone pad heater would be a better solution as well. Kats has those also. Go to the link I posted above and click on Pad Heaters when it opens. EdPruss got me thinking magnetic.
I don't recall for sure, but may have used a pad type oil pan heater on my daughters Mazda pickup when she headed to Fairbanks for college. Also had a battery trickle charger connected to the same plug-in. I have also used a pad type heater under the battery of a truck years ago.
