Honestly wild that this still isn't in the game.
More setup options and filters for TTs would only benefit this mode and players, it's so barebones.
More than just a filter to current car, there's so many options they could easily track and add filters for to make the mode more interesting - silly that TT'ers cannot compete on winter/icy Monte Carlo for example, or with any degradation on dirt and gravel, etc. Don't need additional leaderboards for that stuff, just need icons/columns/text/whatever to display the setup conditions of each run on the existing boards, and filters to toggle what you want to see and compare (which should default to what you just ran).
It still feels so low effort overall, yet it's a very popular mode despite that so I doubt any improvements would be of any priority for them. If they had any interest there, we'd have a global option to disable ghosts after a whole year of begging for this.
