This is our "practice" for the Healing Brush tool in order to get us familiar with the components of said tool.
I find it rather simple as it's basically copying and pasting on a grander scale.
I sort of gave up on the car, but I WILL go back to it in time.
Promise.
EDIT: WENT BACK. I put "after" on the last image, but I didn't like it, so I had to remove it by doing healing brush again. Looks OK.