BMW's response is just plain sorry.
I experienced this sticky steering issue recently.
My Z4 3.0si had been parked in the direct sun in 107 degree Texas heat.
I got in and tried to turn a corner. I noticed more effort was needed to turn the wheels and it was jerky and resistant.
I had read of this defect from this very forum so I knew what the problem was immediately. Thanks to all for that bit of knowledge.
BMW should have recalled all affected vehicles and issued a proper fix. I probably won't spend $2,400 to fix the problem. Again, I've only experienced it once in 15 months.
Sorry. Just sorry!