After reviewing the posts on this message board I decided to recommend a Cosco Scenera for my mother to purchase since she would not be transporting my son very often and it was praised as being a good cost effective and safe second car seat. Now that it's installed, though, I have some questions.

My husband and I both have Britax car seats in our cars (I have a Roundabout and he has a Marathon). They are both installed rear facing with the floor tether and are rock solid.

The Cosco Scenera, on the other hand, is extremely wobbly in the back of my mothers car (installed rear-facing). I'm assuming this is because it does not have a floor tether like the Britax does.

Can someone please tell me how to get the Cosco Scenera installed so it doesn't move around so much? My mother has a 2005 Subaru Legacy Outback wagon if that makes any difference. Thanks!