I would drop the $$$$ on the Xtended warranty if u don't work on the Z urself.
For the following reasons:
1) oil consumption
2) oil overheating
3) plastik CSC failing
4) rear diff silicone bushing tearing
5) I could go on, but I refrain....
The Z is a cost-cutted POS, but w/the right mods and time dropped into it...it can become a fun reliable daily.