I did that on a part of my bike, and on a car. The car ended up being
undriveable because even a little bit of sun will intensely reflect on a polish hood. It really is a pain to drive on the freeway with half an eye open, and one closed. You will alos feel the heat on your face and end up massively sunburned

. On a winding road, the reflaction will come and go, blinding you on/off.
If you still want to go with it, here's how you do it for cheap:
1/ Sand off the paint, better yet, use a chemical to "peel" it off so you don't damage ur hood much.
2/ Sand the alluminum in ONE direction using 800ish grit sandpaper.
3/ Sand OTHER direction using higher grit paper.
4/ Repeat till you reach 2000ish grit sandpaper.
5/ Buff using a alu polishing compound.
6/ Clear coat your hood to protect it from tarnishing and weather.
7/ Dip your right arm in cold water for a week, forget about basic needs like masturbation.
That's how I did it, worked and looked ok.

Personaly Brushed alluminum looks better than polished, I don't like too much chromes on a car/bike. Chrome is cutiecutie, brushed is rugged.

Don't have pictures of the car, here's the bike.
