So the bad news is that once I got it all put together, I gathered all of the various parts, car seats and boosters and tried all of the configurations in my car. My kids are on the smaller side and they all have to be in booster seats and/or car seats. My car has built in booster seats on the sides which is wonderful for Sage but Grace has about 5 lbs. to go for that. At the rate she is growing she might just be 5 before that happens. I did figure out a way to make my car work, it is "almost" impossible and it will be tough to get all of the seat belts buckled, forget about extra space and Sage will have to stop growing while Grace needs to put on a few lbs!
We love our Volvo, it is the best car, it is great in snow, I love that it is not too big and it is stil a car, it has great cargo space and gets much better gas mileage than the alternatives we are looking at. It makes us very sad...but after last night's experiments with car seats, getting a new car is quickly becoming a reality.
On the other hand, maybe Sage will stop growing!