VW hides faults from car owners to avoid warrantee claims.

Truthfully never had an issue with VW until recent. My polo was purchased brand new, I service it with VW its quite new. Recently had to replace a Tyre and the Tyre shop called me to see my exhaust system was terribly rotten and even had holes. I was shocked because my car is newish and I recently did a service with VW,Wheel rotation and balancing and they never said a word... I guess they kept quiet because my exhaust was still under warrantee then? Or is their standards so poor that they don't even check these things. Worse of all I always make a point of asking if everything is fine...i realy thought You pay for quality and good inspection standards. But I guess not. I'm so upset. I was thinking of purchasing another vehicle but I doubt it will be from VW after this.