VW mechanic during routine oil change observed engine oil leak. They diagnosed this as defective rear main seal(crank seal)-transmission side. Removed transmission and replaced seal, after transmission installation test drove then checked for leaks - no more. Personally I never noticed any oil as we have a dirt driveway and it appears this oil leaks onto some cover/pan then perhaps that oil flies away during driving or somehow didn't pool for us to notice this and I don't often check for low oil on this car, never had but will have to now.

Reading about this sounds like something common for several Tiguan owners. I don't know given what I read if I'm lucky to have this caught now or just beginning to experience the horrors of this as other folks have described and going to have more problems with this.