"People have got nice cars and they've pushed and tweaked and done things differently but the other things aren't differentiators. Those four things I can see creating a difference during the year."
It goes to show that certain aspects of a car can act as an obstacle to further development.
Most things on these cars can be copied, it's the unique aspects that can't be easily copied that will give the edge and contrastingly there are parts that can hinder copying and refinement (if in theory all cars converge on the same solutions after exhausting all copying options).
Things such as pushrod suspension, fused beam wing to crash structure can come back and bite a team in the ass down the road if they do come in the way of further development. Though this assumes the team exhaust all it's possible developments to that critical point.