WD Passport 2TB works fine. I've been using mine for a couple months for movies and music, the only issue I've noticed is...if I plug the hard drive in while the stereo is already on, it will say the drive is incompatible. Simple solution...turn the key off, open the door, plug in the hard drive, works flawlessly. I normally leave the hd plugged in all the time, so I never have the issue I mentioned, it's just something I noticed when I first got everything and was testing it all out. I've never had any lack of power issues and it's never missed a beat on rough dirt roads.