The medicine cap sounds like a great idea. I have heard that using the clear measuring cups that come with the large laundry bottle are good also for measuring car wash.
When I first started waxing my car I had received microfiber applicator pads. They work decent enough but I have recently started using the foam applicator pads and love them. Now I use my microfiber applicators for applying interior dressing if I need to work it in.:xyxthumbs: