I was just told by the mechanic that I need a new main seal on a used car I just purchased: 2006 Subaru Forester 2.5XT turbo 139k miles. He said that he can see the oil when he looked under the car. How can I verify that's an issue - I haven't noticed any oil myself, should I be looking for oil drips under the car or a burning oil smell?
Seems like an expensive job so I don't want him to pull out the transmission and get into it if it's not totally necessary.