Had this kind of BS pulled on me when selling my Audi last year. The guy did one better, he took the car for an "inspection" at a well respected shop and the shop came back with a "list" of almost $4k worth of work that the car "needed". Funny thing is that almost all of the work it "needed" was just done in the 3 months (1500km) prior to me putting it up for sale (timing belt/waterpump, brakes, shocks/struts, control arms etc.).
When I picked the car up from said shop, I "thanked" the owner for pointing out to me that I have been really "ripped off" by my mechanic whom I paid to perform the aforementioned work. I then told them I will be reporting my mechanic to the MTO and Ministry of Consumer Affairs for charging me for work that wasn't done.
The owner went white and the tune totally changed, that they actually didn't check the car, but the Audi dealer did... To make a long story short, the buyer, a friend of the shop owner was trying to use this as a tactic to beat me down on price.
Sorry for the rant and good luck selling the car. A right buyer will come along!!