Tinkering is performed to remove dents, scratches, chemical erosion, environmental erosion occurred on the exterior surface. This will improve the aesthetic appearance of the vehicle.
Especially: to repair, adjust or work with something in an unskilled or experimental manner
Tinkering improves hand-eye coordination and fine motor skills. It also promotes exploration and creative expression. Many scientific journals and studies report that emphasis on only intellectual activities like memorization of letters and numbers is far less useful. And must be accompanied by skill-based education.