If like me you're paranoid about your new baby in the rear-facing car seat (especially if you hear them choke like I did!) then this is a great item. Very easy to fit and very cute.
Two slight negatives - if you have anything hanging from the car seat handle (think maxi-cosi) it will obstruct the view of your baby, so unless you move them to the other side the mirror is useless. Secondly, if anyone sits in the middle seat (as my 9yr old nephew did when I picked him and his brother up from school) the mirror moves out of place very easily and gets marked.
Otherwise great little product!