Done.  I went to another dealership when I had continuing trouble after receiving the car back after the cylinder head replacement.  The new dealership said the Valvematic (thier words)  needed replaced, but Valvematic is a system, I think, not a single thing.  There is a long list of parts I have.  If I get 4th cylinder misfire code again I will arbitrate for replacement vehicle.  That would be the fourth 4th cylinder misfire code.  They have given me a free extended warranty, 125,000 miles or 8 years, which I appreciate (after I asked for it twice).  That takes me to 2021, and I could probably still get a pretty penny for it if there is no more trouble.  It will have pretty low miles.
Understand your loyalty.  I def had bad luck with this one.  Am forced to hang onto it for a while due to the money I would lose if I sold or traded right now.  I've only looked at KBB.  But after I've had a chance to drive my car for a little while and think about it I may see what a dealer would give me for it.  I pimped my Corolla with alloy wheels, fog lights, beveled strips on the side, the door sill plates that say Corolla.  And I bought the $500 interior/exterior protectant.  My LE Eco Plus 4 Dr Sdn was 22,300, all said and done with taxes, delivery, et al.  I would lose at least 7K today, according to KBB.