Start with the object you want polished - AFM, rocker cover, turbo housing......
Seeing as there's lots of alloy under the bonnet of the 5, there's plenty to choose from.....
Start with the skanky old bit of metal you want shiny..... eg. turbo:
The first process is sanding - anywhere from a 400 grit to an 800 grit is fine - you want to take all the cast marks and remove the 'burry' surface. You can use the dry paper to start but a cheap car polish also works very well as the cutting paste - it mixes with the microfine metal sandings and makes an even better and smoother abrasive. If you dont want to sand by hand, a mouse (detail) sander works very well.
This rocker cover shows a half and half stage - I've polished one side using the method I'll describe below, and the other half is just at the sanding stage.
Once you have the metal surface 'smooth' you need to start to buff out the sanding scratches - you do it exactly the same way as you would polishing the paintwork. A cheap polishing kit from the hardware is a good investment and makes the job easier. Apply polishing paste to the polishing wheel (ragmop) or to a soft rag, and start polishing..... it is hard work, and you need to keep at it, but it will shine up.
I took this turbo from the pic above to this below:
And here's the rocker cover end - it was just as you see it on the car from the factory:
You can also use a ragmop attached to a bench grinder - this is how most workshops will do it - I have and use both, depending on the details I'm after.
There's a few here who have successfully blinged their cars - perhaps a few others can add their $0.02 here.......
