u/munkimafia

My wife’s 2015 GLA has one door panel that has lost all its shine. Pic comparing it to the door next to it. Never been replaced, so I suspect some sort of cleaning chemical was left on too long without rinsing. Feels Matt to the touch. Any advice on what to use to bring back to normal? I was looking at Autoglym Advanced Paint restorer, I don’t have a polisher so would be doing it by hand. It’s only one door, so not too worried on the effort required! Thanks in advance for any helpful suggestions