Which is Bigger, the Jaguar or the Fiat 500

On my way to Florida I stopped at gas station in Kentucky.  I parked my car and when I turned back to look I noticed something that seemed to be an optical illusion.  The Fiat looked like it had a bigger interior than the Jaguar I parked next to.  So the question in my mind is which is bigger?  The Jaguar is the "X" Type which is the small four door Jaguar but we usually don't think of them being smaller than a Fiat 500.  The "X" type is based on the Ford Mondeo (Contour in the U.S.) so it shouldn't be smaller than a Ford Focus.  Truth ids the Fiat is tall and is mostly interior volume.  I have been in a Jaguar "X" type and they sit low and are not known for being spacious.  But the Fiat is a bit narrower and definately shorter.  So if you are not the driver or the front seat passenger, the Fiat is smaller.  I have also noticed this wierd size phenomena with the Toyota Yaris which is about the same size as the Fiat 500.  The size prioty on the Yaris is for interior volume and when parked next to mid-size cars the Yaris appears to have an interior that may be larger also.