Do I need to use car wash mud for a one-and-a-half year car?

Depending on the paint surface, it needs to be used if it is rough or attached to dirt. After removing the stains with car wash mud, waxing or paint surface water coating will make the paint surface smoother and brighter.
The role of car wash mud:

Cosmetic clay is a quick and safe way to smooth the surface and remove dirt without damaging or thinning the crystal oil layer.

One of the reasons for using beauty clay is to remove brake dust. The brake dust stain attached to the rear bumper and adjacent surfaces is a surface stain that contains metal. The use of beauty clay can safely and effectively remove it.

Car Care Wash Tool Magic Clay Bar Cleaning Mud Cement Dirt Removeal Manual Clean