I`ve used my bottle of SSR2.5 on a bmw 740 and my sister`s car, little escort and I think i`m using to much of it. Theres about 3/4 of product left in the bottle. So my question is: am i using way to much product or is this normal?? 4 fl. oz seemed a lot for only 2 cars. btw this was used with the PC both times.