DS2 is going up to the next size car seat as getting too big for the baby one that can just be carried around. DP has a small car and often gives lifts to a relative with bad knees, so need the front seat far back. We have just tried the car seat with isofix that we used for ds1 and cannot put the front seat back far enough.
Do smaller depth rear facing seats exist? Happy to use non-isofix if that would fix it as they might not come out as far. But rear facing is a must as baby is far too young to legally face forwards.