Can't connect to CarPlay

I've just purchased a new SEAT with the VW MIB II system. The salesman showed me how he could connect his iphone with the CarPlay in the system (in my car), but when I tries with my iPhone 5, the MIB II system tells me to unlock the phone and the pairing processes is aborted.

Since I'm using my phone in my work, I've a certificate on the phone + using an Exchange account. I remember that when I configured this exchange account, the behavior changed in my phone so that I'd to change the phone PIN periodically, in addition, the phone goes into locked mode rather quick (a minute or so). Seems impossible to remove that behavior without removing the mail account. So I did that - and I upgraded the phone, restarted it, reconnected and so on - multiple times - without any luck, same problem.

However, it still can't connect with the CarPlay unit. I'm confused and annoyed....