My 2 yr. old daughter has been in a spica including one arm for two weeks now. We found a toddler size car seat at Babies R Us with no high sides that works with the 5-point harness. Also got a new stroller with low sides and tray. As for diapering, we use the hospital size maxi pad with a #2 diaper on top pushed in the hole. She tells me when she goes and I just change her immediately. She requires a lot of attention and carrying around. But we prop her on pillows at the kitchen table and she uses playdough, markers, beading, etc.. You'll get through it!