If you have a forum member living close to you and have pre-refresh alloy wheels (19 or 20") without the run flats, I think you should try swapping his alloys onto yours and see if the problem goes away. By all means buy him a drink or pay him for his time, but it would be hell lot cheaper before going for coilovers.Sounded like good advice. I took the car into the service center today. They did a test drive and later a visual inspection. They said it’s “normal” and “working as designed”, and the car is “stiff” because it’s “sporty”. (They also checked the tire pressure & tread.)
No amount of arguing that it's the worst-riding car I’ve had and the kids in the back don’t want to take this car on trips made them reconsider.
Looks like coilovers next.