Thanks for letting me know. Even though they didn't do anthing to fix the issue because they couldn't replicate it, it is still running fine.

My husband was talking to the technician, and he did say that the way it would shake a few seconds then stop, then shake again (quite rhythmically) that it sounds like it might be the altinator clutch. Apparently, these cars have clutches on the altinator. Thought I'd mention that, too.

Good luck with yours... sorry they didn't fix the issue the first time.