Congrats Mr Horse!!!
When I had my GTV I'd take my 1st born all over the place
Unfortunately, it was in the front thereby ruling out all but one other occupant straddling in the back.
Realistically, it cannot be done
So take the advice and get a cheap runaround (YOU DON'T NEED A PEOPLE CARRIER YET!!) and keep the GTV for sanity, special occasions, the odd QUICK trip to the supermarket to stock up on nappies, milk, wipes, milk and some nappies
I managed to hold onto my V6 until I started doing more mileage for work. I then went to the GT (via a Ph2 MR2......don't ask) and the (now) toddlers aren't let anywhere near it unless they've completed a through hosedown and defumigation regime
Well, they have to atleast take their shoes off, not eat or drink anything (probably not too kind for long journeys) and keep the grubby mits of my leather!!
They still love going in "daddy's car" despite my merciless conditions .......
"Go Daddy, Go Daddy, Go Go Go!!!"