Thought I would add a post script here, it turns out it isn't my SVX that is leaking oil, nor is it my son's car. Is my husband's work truck!
I had a panic attack for no reason and feel like I dodged a bullet. However, I got a lot of good information from this thread and appreciate all the suggestions. I am switching back to regular oil. I have started my own mini-manual and list of things I want checked for next mechanic who works on my car.