Asked everyone what annoyed them about the old one, then reproduced every complaint myself before believing it.
A load-bearing rear wheel adapter that was heavy, awkward to adjust, and could not be serviced without dismantling more of the car than the job warranted.
New to the team, started by asking other members what was wrong with the assembly and then reproducing their complaints rather than taking them on trust. Set 4 explicit objectives before drawing anything.
A 52% lighter assembly, serviceable with a hex key and manufacturable in the team's own shop, with a safety factor of 2 on the vertical load case in FEA.
Checking cornering and braking was worth the time even though neither governed - the car travels slowly enough that the vertical case dominates, and knowing which case governs is what let the mass come out.