Margarine - Should I Use It to Lube the Car?

Go au naturale or not go au naturale? That's a question. Use butter or use margarine? That's another question. This source says to try this experiment with a container of margarine:

"Open it, then leave it in your garage or in another shaded area. Within a couple of days, you will notice a few things: First, it doesn't rot or smell different. Second, nothing will grow on it. And finally, no bugs-not even those pesky fruit flies--will go near it. That should tell you something."

Well, even if it turned out as stated, does that make margarine a bad thing? I suppose that one could take some calcium or iron or magnesium or zinc and put it in the garage and see if anything ate it. Just because nothing touched it, doesn't make it "bad" for you, does it?

Tell me how it turns out.