I bought my Z2 from cartronixplus.com as well. I'll describe the situation and you can come to your own conclusions.
I went to the website to order the unit. I couldn't find any information on whether or not the harness was included for my vehicle. Then the internet account registration crashed in my browser.
Undaunted, I called their number. They took my CC info. According to the rep, I was getting the last in-stock unit. I told them about my account creation issues, and they said they would fix it. Okay.
Wait two days, no shipping info. Check the website, my account is still bork