For a quick bodge to sell it you could try cutting back the paint where the lacquer has peeled and blow it over with a rattle can. I've done that before and it is OK on a cheap car. You could remove the lacquer completely from the rest of the tailgate to get a more even look or if you want to do it properly then sand it all back and spray it. Personally I would try the bodge first as it is quick and cheap for a car you are selling.
Understeer: when you hit the wall with the front of the car.
Oversteer: when you hit the wall with the back of the car.
Horsepower: how fast you hit the wall.
Torque: how far you take the wall with you.
I'd get a blade, Stanley knife type, and gently lift off the remaining lacquer, but don't try and force off any which is still stuck, then carefully flat back any remaining until you're down to the colour coat. Providing it's still decent enough, it shouldn't need any more paint (unless you rub through flatting back) give it a few coats from a rattle can, then polish it back up.