Carseats- How important are the "head wings"?

[sosurreal09]

DD has these on her Radian for side protection but someone got us a Radian for the new baby due in May and it does not have those. How much do they matter?

[chickabiddy]

Short answer:  we don't know.  There's no evidence proving that they matter at all.  We know that the safest thing to do is to rear-face to the limits of the seat, and that rear-facing provides substantial side impact protection in any seat.

[sosurreal09]

OK we do ERF anyway DD is still RF in hers and she's 28 m/o. Thanks!