My Z is a POS

Nixin

Sell it or trade it in for another Z. It is a great car and unfortunately you got stuck with one that had some issues. That said, they were not HUGE issues like an engine or trans. replacement.
Most of the issues you had were issues that were covered under warranty. Ask the MOOOstang, Camaro, Challenger, etc. owners just how many major malfunctions they have had on their 'whips'? Your Z issues, although a major PITA for you, will be minor in comparison.