I seem to remember the manual recommends using a stong jet of water (not power washer)to dislodge brake dust and dirt then to drive the car afterwards. If you use the brakes fairly hard ie drive hard you don't get a problem with the standard brakes.
Of course you get rattles with a sports car that's driven hard

but less with Porsche than most others especially Italians which are terrible!!

My latest rattle is fixed by a piece of rubber wedged between the rev counter top and the dashboard top