Career mode improvements that should be relatively easy to add
The recent expansion added a few noteworthy improvements to the career, such as random weather in the 2024 season. However, there is potential to do more with this and create a career mode with highly improved replay value. My main suggestion would take a page out of EA PGA's book; A rotating season schedule.
Players with the expansion would play the 2024 schedule in odd numbered career seasons, and the 2023 schedule in even numbered seasons (or vice versa). This would naturally require some reworking of the '23 season to include random weather, and setting up the legs so that every WRC event has at least 2 Sunday stages on at least the Long setting. However, it would only be one new schedule to create, and it would even improve the career for non-expansion players (who would be solely using the '23 schedule).
The points system has also proven highly divisive this year, so I would like to suggest that the player gets to choose at the start of each career season which points system they're going to use (applicable in WRC/WRC2). That way, anyone who is a hardline traditionalist regarding the points isn't put off by the purchase of the expansion locking them into the Super Sunday system, as they can opt out of it. This is also why I brought up reworking the '23 legs, as then you can have the '23 season with the '24 points or vice versa. Maybe even include 2025 points as an option if the proposed change is passed.
But to get back to the main point, I think having the career mode rotate between the '23 and '24 seasons would make the mode more fun for expansion owners, as that way events only repeat 1:1 every two years as opposed to one.