Re: 3 kids
If you like the IS you might want to look at the new 3 series. Its a little bigger, especially in the rear while still being small and sporty. The IS will be totally refreshed this year too, and all new for 2013 most likely.
My main concern with the IS would be the rear facing seat, once he's out of that it might be okay...
2015 Lexus LS460 AWD, Nebula Grey w/Light Grey Shimamoku Interior
2015 Kia Sedona SX-L, BlackBerry w/ Dark Burgundy Interior
Previous Jeeps: 2014 Grand Cherokee Overland; 2011 Grand Cherokee Laredo X