My sister rented a car tonight for a road trip tomorrow. She installed her two radians rear facing in the back. The one on the passenger side installed well. The one in the center wasn't as secure because the boot seemed to be interfering with some hard plastic things in a couple of places at the seat bight making the seat sit crooked. We tried installing it with a tightly rolled towel at the bight and the install is very tight. We didn't find anything in the car seat manual either way about using a rolled towel. I see older threads here saying that a rolled towel is not allowed with a radian. Is that still the case?