Extensive numbness 2 1/2 years after facelift- any hope of recovering sensation? Can auricular nerve damage ever be repaired?

it is unlikely that your numbness will recovery if it has been 2.5 years.  However, your patter of numbness if very unusual and does not correlate with the surgery.  There should be no reason for you to have numbness on your scalp, front and back of your neck.  There is something else going on here and I would consult with a neurologist for a proper neurological assessment.

Most patients recovered near full sensibility to the face in about six months. Damage to the greater auricular nerve can create numbness around the ear. It should not be damaged during the facelift but if so can be surgically repaired.

This is definitely unusual. Many patients describe temporary numbness in the cheeks and possibly the ears that resolves over the first few months following surgery. Typically, if numbness is going to improve it will in the first 12-18 months following surgery. Unfortunately, I am not aware of any options to improve your numbness at this point. Stephen Weber MD, FACSDenver Facial Plastic Surgeon