I was on here a few months ago and needed a narrow car seat for our vehicle. We have the Marathon and by the other window was the infant seat. A lot of you recommended the Radian so we bought that for my 3 yr old and took my baby out of the infant seat and into the Marathon. We needed a slim car seat because i have a 15 yr old that has no where to sit! Well we got the Radian in and unfortunately there is no more room than before. We are going on a trip soon and i need to know if there is anyway possible that a radian and Marathon can go beside each other so my son can have a window seat. My husband says there is no way that would work because at least one of the car seats would be on a slant because of the way the seats are sunk in.. sort of bucket style i guess. We have a 2004 Hyundai Santa Fe. I hope someone can recommend a way to put these seats in to have more room.