Had a similar experiences to another user here, or I thought i did at first... that being the "vibration" did not appear to be functioning... with a little playing around with the device I come to find that where the baby sits makes a HUGE difference. ie: with no baby in the chair, vibration nearly non-existent especially the "handle" was tucked away. Other than that little learning curve, I have to say this is the best product by far I have ever seen. In the 6 weeks prior to getting the "crusin' motion soother" I am sure I doubled if not tripled my fuel consumption. I have yet to take her out in car since. There are only two complaints I have about the device;
1) Batteries, although I have not worn out a set yet, I just hate anything battery operated. But this one works so I'll bite the bullet.
2) no aux input for music say from an MP3 player. I can't speak for all parents, but our little one is not really a fan of the midi styling that most products provide. Thank you fisher price for a great product :)