Rib rack plus foil?

I'm going to do babyback ribs for the first time this weekend so I've been checking out a few recipes/vids. All of them have you wrap the ribs up in foil for the last 1.5 hours. The problem is that I'll probably have to use a rib rack to cook them. In this situation should I forego the foil? Wrap them then put back on the rack? Wrap them then stack them? What do you suggest?