So a strip wash is an alkaline based soap applied to a vehicle that will take any old wax, sealant, even weak ceramic coating off along with bird droppings and traffic film. Clay bar is typically a piece of clay used to remove foreign objects like brake dust particles, bird droppings, bug/guts and rubber transfer from the surface of the paint. Vehicles that are driven often and have not had a clay bar service performed can accumulate lots of unwanted imperfections and pick up unwanted contamination from the road which can significantly effect the performance of any protection you add to the paint as they are not designed to stick to those contaminants. You should expect to perform a strip wash with a clay service annually or bi annually on a vehicle being used daily and parked outdoors “parking on a very busy street and especially freeways can shorten this time” this is the best way to keep your paint looking great and your paint protection doing the job you ment for it to do.