I was just about to post then same, car 6 months old done 7000 miles, alloys been hard to clean, spent loads of time cleaning wheels with car shampoo only at the weekend, and under the dirt, there is corrosion on all 4 wheels, the side that faces outside, the problem can wait, but as my local dealer loathes to do warranty work, it will be interesting to see what happens.
The car is 2011 model year 1.6 CRDI comfort again with 16 inch alloys.
*****dont spray with WD40 as it will go on the frictional material & you will have poor brake performance******