I thought you're suppose to turn them around when they reach 9kg? We don't drive but when we go in friends and mil's car he's still in his baby car seat and is rear facing but he looks so uncomfy so we're getting him a forward facing one x
It's age 1 minimum here in Canada and the US... 9kg is a
minimum in the UK.
It's age 1 AND 20 lbs in most states in the US. That being said, we have a small car and my son's convertible rf seat fit just fine. I didn't think there was an issue with legs dangling over an infant seat as long as she was in the weight range? I don't think mine has a height spec on it but even if it did, I don't think she is over that.
With regards to it fitting in the car backwards, I think it depends on how tall you or whoever is in the passenger seat is (depending on what side you have lo on). DH and I would have our knees in the dashboard with a rear facing convertable behind us in my car lol, it's practically that way with the infant one rear facing and I actually told DH that I think we need to get me an SUV because my car was definatly not made for someone with two kids in the back seat lol