2001 Volkswagen Jetta For Sale by Owner in Aurora, CO

Burns no oil, new battery 3 months ago, new tires 3 weeks ago.  Alternator was replaced with a new one in 2012.  Only Mobil 1 synthetic oil has been used in the engine.  I am the only owner and have driven consistently and carefully.  I bought her new in spring of 2001 and enjoy and appreciate driving and owning her, even more than I did when she was new.  (I grew up in sail boats, which is why I naturally refer to a car as 'she'.  Her only very minor accident was in 2005.  In a downpour of rain, a jeep hit us at slow speed from behind because the driver had such limited visibility.  The trunk lid was a little bent and was immediately repaired.  No damage at all to the frame.  

What things are wrong with this Jetta:  When the sound system stopped working quite a while ago, I decided not to replace it.  I am very happy with silence and knew that a new owner would have his own preferences for a sound system.  The trunk lock stopped working recently.  It is clear that the electrical impulses from the key and the door work fine.  However, the excellent shop that replaced the broken rear view mirror insisted on an electronic diagnosis that cost $150.  I could not afford that diagnosis.  A new owner can fine a technician who can simply replace the lock.  The air conditioning stopped working recently.  Why would I fix it when the weather was cool and getting cold?