Julie, how much does your 10 year old weigh? I am thinking I may have to take my almost 10 year old out of her booster seat when the new baby gets here. I don't think there is any way I can fit three car seats in the small back seat. I have the Infinity QX 4. Hoping to get a mini van, but that won't happen for a while. Right now I have two Jane's, and am leaning towards the Chicco Keyfit 30 for baby.