A 350GT as a peacemaker? Rear seats for baby, Zed for you. Also you have the luxury of a car designed to have rear seats, so not a huge PITA to get in and out of (not mention if the worse should happen #fire ).
If it's more the fuel bills than the number of seats, a 350GT isn't going to help. May as well get a 335D coupe, map it to death and kill three birds with one stone (more seats, diesel, still goes fast).
Just try not to look directly at it from the outside