Audi Certified pre-owned warranty question ?

When a dealer does the 300 point inspection an Audi is it an optional
purchase for the buyer? I know it costs them money to do this thorough
inspection so I would think they would add it into the listed price of the
car. The reason I ask is because I'm about to purchase a 2001 S4 from a
dealer in Chicago and they listed the car as being Audi certified on their
site and the car was on Audi's site as being certified also. They listed
the car at $28,900, but want to charge me for an extended 2 year warranty.
It seems like the dealer is trying to pull a fast one and/or falsely
advertised the car as being certified. Just seems weird that if the car was
certified, why would they push an extended warranty. Also the car has low
miles, so maybe the certified inspection was just done "on paper." TIA.

--
Greg