I've connected this to the AUX port in my existing Clarion head unit, and it works like a charm. Audio from the phone is crystal clear, and hands-free calls are higher quality than plugging directly to the port. Callers had no idea they were over Bluetooth. I also love the auto-off feature, so I can just jump out my car upon reaching my destination without worrying about powering anything down. It also feels sturdy (another similar product I tried felt like it would break if I breathed on it too hard). The only "con" I could see would be it doesn't have an auto-on (like when it receives power), but that's a nitpick. Perfectly contented with the purchase.