The OP was 4 doors
decent sized boot
decent power 150kw +
decent handling
relatively modern 2006+
I have searched the net and haven't really been able to find this mythical 4 door Elise with the decent sized boot and room for a baby seat. I have heard that with a bit of jiggling you can get two toothbrushes into an Elise.
Not only that, the addition of what goes in the baby seat usually has some impact on the driving habits of responsible adults. Keep the MR2 toy for your jollies (it's more fun when everyone is driving in the same direction) and buy a civilised family car that provides you with safety, quiet and comfort.
Look forward to seeing you again in January 2014