What is the weirdest thing you had to account for when building the perseverance rover?

seen from United States

seen from China
seen from United States
seen from Netherlands
seen from United States

seen from United States
seen from United States
seen from Russia
seen from China

seen from Canada
seen from China
seen from United States
seen from Singapore

seen from Netherlands
seen from Egypt
seen from United States
seen from Germany
seen from United States
seen from Argentina
seen from United States
What is the weirdest thing you had to account for when building the perseverance rover?
what is the biggest challenge in the preparation of such a mission and how do you handle it?
what has nasa and jpl learned from opportunity that has helped with developing this new project?