I noticed a similar situation with mine shortly after changing my front pads...changed to an aftermarket performance pad...can't remember the name...purchased from Mopac. I noticed I seem to see more brake dust on the wheels with these pads than with the Nissan ones. When I clean the wheels & spray water around the caliper area, I don't notice any noises for a while. I think it might have something to do with dust collecting around the caliper/brake pad area. These pads seem to stop as well...maybe a bit better than the stock ones. If I had to do it over again, I'd probably use the Nissan ones...got over 70,000kms with them with no problems, no weird noises, & less dust on wheels.