Just for future reference on SR for ANY ride. If you decide to do that, you need to be fully prepared to be separated AND that there could be a wait - sometimes lengthy - between people riding (depends on the ride...Test Track (assuming they keep their 3/3 set up usually goes fast, EE is a crap shoot, RnRC you're almost better just going through the line). So whoever goes first may have a while to wait before the rest of the party gets through.
ETA: Even with Test Track (again, assuming the configuration stays the same), there is no guarantee that your group will be split as you desire. On Radiator Springs, there was a group that had a young-ish child and the mom had to let a couple of legit single parties go between her with the younger kid (who probably shouldn't have been allowed in SR anyway) that she wouldn't let go alone and her older kid who went in one car and then there was a series of cars that would only take 1.