After washing your car, pay attention to how water behaves on the surface. Many traditional car waxes make water form beads that roll off easily. However, some waxes and paint protection products are designed to encourage sheeting, where water runs off in smooth layers. Both can be signs of good protection - the key is whether the behaviour changes over time.
If water no longer beads tightly or sheets smoothly, and instead clings to the paint or leaves large wet patches, your wax layer is likely wearing away. Other signs include paintwork that looks dull, feels rough, or becomes dirty again very quickly.
Regularly waxing a car restores gloss and adds a protective barrier against UV rays, road grime, bird droppings, and other contaminants. For most cars, reapplying wax every 2–3 months helps maintain paint protection and shine, though frequency depends on driving conditions and whether the car is garaged or left outside.