Yes, it is accurate..but you must understand that not all OBDII data is created equally. Not all vehicles report the same information. If you want to see what info the Z will report, you can download the Rev Lite version for free. Granted, it won't five you any actual reporting but at least you will get the gist of the type of info you can expect.

Let us know on this thread if you do pull the trigger on the wifi solution, k?

Ps. Check here for the multiple apps that are supported: PLX Kiwi Wifi - Connect your iPhone / iPod Touch to your car's OBD2 OBDII Port.