Wow, car seats are more complicated (and better) than in the 70's! Has anyone out there installed the Britax Marathon in a 2003 Subaru Forester? We had gotten an inexpensive Graco and now recognize that as a mistake. Want the safety and flexibility of the Marathon, but can't get clear on whether it will fit in the middle and still let a person sit on the side. Any advice welcomed if another seat would be better. This is for a 23-lb, 14 mo old grandson, who --after reading this site -- will be...