i really dont recommend magic eraser. those foams are quite abrasive. they belong on pots and pans, stove tops, kitchen sinks.
as for the door panels Prima Nero/Aerospace303 will do a great job of bringing back the dark black color without the greasy feeling. Nero 50/50 with water will be best though from my experiements. it's best to apply BEFORE you have any scuffs though.
for the arm rests on the door panels try cleaning it with Griot's Interior Cleaner on a MF towel. works great.