New Member Couple of Questions

Hi there, new to the forum and i have only had my s3 8p just over a month but am loving every minute of ownership. Though i have already started with the mods and i have a couple of questions i need answers to if anyone could help i would appreciate it.

Firstly i retro fitted a rns-e chrome edition....and i havent had a single problem coding wise that i can see, all the speakers work fine and the dis is all perfect. But is there no settings that need changing on the unit, or that will need vag com coding? Ie wheel sizes...

I do plan to retro fit the FBMFSW and currently my car has no multi function. So basically i want to know which Ring i will need for the air bag and wheel. And what is the ecu for the steering wheel? I guess all of this will need coding? Is there any 'How to' ?

Next i am looking at getting a miltek non-resonated and de-cat and wondering if anyone has any sound clips?

Finally am looking at getting a forge dv, now looking on the website there is the fmfsitvr, now this is a re-circ as i understand, now what is the spacer i read about? FMFSITA? How do they work?

All information will be greatly appreciated and am sorry if this is a long boring common message.....but i have spent a week or so trying to find the information.

Thanks Ben.