Do you have the Discover Media or Pro? Does your Radio have knobs? Your car from year should have a MMB2 or MMB2.5 (without knobs)When my car was using CP600, the voice and video were out of sync, and the buttons on the steering wheel could not fully respond. After I switched to ApplePie, this problem disappeared. I haven't encountered the sound lag problem you mentioned. I have used it for up to 3 hours, listening to songs and watching videos. BTW, my car is Golf 2018.