5 STAR SHINE's PPS formula was tested for durability by an independent laboratory. The laboratory concluded that even 150 washes could not wash off 5 STAR SHINE's patented PPS coating. In fact, 5 Star Shine's PPS formula was still shining, beading water and protecting the surface after 150 washings while a name brand car wax had already completely failed when measured at 20 washes! 5 Star Shine's PPS formula is the only product to pass such a test. Click here to view the Lab Results.