The ability to buy/sell/gift barn find cars: Some people don’t want some of the barn find cars at all, and I, and I assume some others, want secondary copies of barn find cars so we can have a tuned and stock version of it. This was allowed in FH4, why not in FH5.
A MUCH LARGER garage capacity: Some people love having a sizeable collection, and as far as I know, 1000 is the current cap.
Organise by custom categories: The ability to organise our cars into custom categories, or have a labelling system so I can sort between cars for racing, drifting, etc.
I’ll come up with more as they come to mind.