A week ago Spotify reproduced without problems on my 2015 Ford Fiesta Sync, I'm premium and not detected now. Since the apk updated. I already uninstalled and delete vehicle information and my Samsung S5, and still detect.
Please read the guide linked below for details on the most common issues and how to fix them. Usually a clean install is the first step to take and resolves most of the usual issues; the guide details the steps to take to ensure a full 'clean installation' is achieved - This includes checking redundant folders and a REBOOT!