I have the Q2 and space wise its perfect so I can imagine with the Q3 being bigger it’ll be fine
My dad had a Q3 and there wasn’t much space in the back, the boot wasn’t overly big and my son struggled with space in his booster seat and my daughter joie ispin only fit passenger side as the front seat was far forward
I have the Q2 and space wise its perfect so I can imagine with the Q3 being bigger it’ll be fine