Maybe this will make you feel better about rear-facing seats' SIP even without headwings:
When we crashed, Maggie was in a Zento. No headwings, pretty open space around the head and really the shell didn't seem that deep! Here's a pic:
Sorry about the poor quality; it was taken at night, in the dark, with a crappy cell phone camera before I got a better phone. LOL. But that was taken about 2 months before the crash, so it's a good idea of how she fit in the seat at the time. (Minus the twisty strap, which I fixed every time I buckled, but this was just taken because she wanted a pic in her seat.)
Anyway, you can see- there's not a lot of what we'd think of as "great SIP features", right?
Ok, so in our crash, first there was a side impact on the side away from her, but then after we spun, we went down in a ditch in an offset-frontal- that was on her side- and then over onto the side she was on. As we scraped along the side she was seated on, and I was too,
my arm went out the window and dragged along the ground for a few seconds. My neck took a huge beating as my head flew to the side with nothing to stop it, leading to part of the nerve damage that kept me in a collar for two weeks.
Her arms and legs stayed cradled within the shell that she'd been pushed into in the frontal portion of the impact.
Her head was stopped by the foam and shell of the seat and supported there for the remainder of the crash until the roll. (Actually, the neck/head thing happened twice- during the initial and the secondary/tertiary impacts. All of which had at least some side impact component.) Result: I was in a collar and restricted from lifting for two weeks, and had massive amounts of stitching on my arm. She didn't get one scrape or bruise, only a bit of dust blown into her hair and sticking to her skin. Scared, not hurt, not one bit. In that open-looking, shallow-looking seat- just because she was rear-facing.
I know you've heard the story before but I thought that hearing it from the perspective of what happened to two of us seated on the same side of the car, during the same impacts, and seeing a pic of her in the seat would illustrate just how safe rear-facing is, even in side-impact cases, even when the shell doesn't seem to offer
much extra in the way of SIP.
In fact, looking at both pics, it seems she fit the seat's flares and curves a lot the same way your little one does- so I think it would do an excellent job in a crash.
