I have a 05' A6 3.2

Headlight housing pass side looks like someone tried to clean it with a headlight restoration kit and burned the plastic so should I just leave it, replace it with factory, or just go aftermarket I like the housings with the black chrome background and the led strip in between the light n turn signal?

Also how hard is it to replace the taillight wanna do kinda the same thing as the headlights (if I decide to go with aftermarket)?

I want to go with an HID Fog light (3000K/Yellow) do I need a Error eliminator or a relay resistor harness? I don't want to get any warning lights inside the car. I know it's an H7.

Aftermarket alarm work with existing alarm Don't wanna lose the push button start

Does anyone have or know of a good Exhaust system to change the sound and give me a little more HP?

I know a lot of Audi's have a Turbo so is there one I can get for my 3.2? or any other power adders?

Sound system I know it already has a Bose system in it and don't get me wrong it does sound decent for being 8yrs old but, I just want a little crisper highs/mids/lows I know I personally can do it but, the thing holding me back is all the tech in that car especially with the MMI and I'm sure it already has an amp in it. Is it worth the trouble or can it be done/have you done it and do I need any special parts to do it?

Also, is there any way to change the CD changer to a more updated one? The one I have won't play a MP3 CD just CD's with up to 20 songs depending on the size of the song. I like a lot of different music so I have to keep CD's in the glove box and change them out which is a pain. So, I'd like to go to a newer CD changer if possible and at the same time I don't want to lose the functions of the current CD changer if it's possible.


Thank you in advance for all your help, time, and opinions with these ?'s. I do appreciate it