Steve Q

I'd recommend a diagnostic check to see if any fault codes flag up 

Try eBay I'd say. 

Just an update I got hold of further information regarding the engine and gearbox codes thanks to Luke Voss, a member of the A6 c7 UK club. 

This is how you change it: 
2.5 Renewing bulb for dipped beam head‐
lights
Removing
– Switch off ignition and take out ignition key.
– Turn light switch to position “0”.
– Remove appropriate front wheel.
– Remove relevant front wheel housing liner ⇒ Rep. gr. 66 .
– Loosen locking bolt -1- a few turns.
– Release retaining tabs -arrows- and detach housing cover for
dipped beam headlights from headlight housing.
 
Audi A8 2003 ➤ Electrical system - Edition 08.2014
132 Rep. gr.94 - Lights, bulbs, switches - exterior
But you can take the bumper off and headlight out if you wish. Pictures for reference to show what it looks like behind the wig and bumper etc. 
 

Think it could be the rod that attached to the door handle. 

You're lucky. I'd still recommend a gearbox oil change to be on the safe side 

From looking online this spec is very rare. 
I'd estimate it's worth between 2-3k. 

Wowzers! 

You will find it is an offence for the driver or any passenger to not wear a seatbelt in any country in western Europe. On top of that the driver gets the fine for each passenger not wearing a belt. 
Not only that, I doubt you'll find a company that will deactivate the chime as I believe it's an offence to tamper with safety systems regarding seatbelts. 
Furthermore, if these systems are found to be tampered with then your MOT and insurance is void. 
I just can't understand why passengers wouldnt want to wear a seatbelt, the world as moved on since the 1950s/60s & 70s. 
I'd advise your passengers to watch videos on what happens when they don't wear a seatbelt. Needless to say, the one sat behind you can ultimately kill you as they hit the back of your seat! 

You'll need to get a certificate of conformity from Audi which is free of charge. 
email the address as below with VIN number of your vehicle, name and full postal address.
cocrequests@vwg.co.uk 

Not heard of any other cases. As it's a new car I'd recommend for you to get it checked by Audi.  As it could be a faulty seal or nis-aligned door. 

Apologies, I've just re-read your post, should have read it properly the first time 🤦‍♂️ If it's just first gear could it be a linkage? 
My wife has this similar issue on her Corsa many years ago. 
Engine wise, plans are afoot to get it back in the road. Early days yet but watch this space 😉

Yep 5w 30.is correct 

It'll be expensive to upgrade the screen. 
Regarding the SD card it doesn't have to be a 2015 one. 

That sounds about right to me. You could always get a diagnostic check to see if any fault codes flag up. 

Powerflow do great exhausts. 

Make a note of the codes. Then clear them. See what ones come back and change the relevant parts on the codes that return in the code reader. 

I'd recommend a diagnostic check to see if any fault codes flag up. 
The symbol looks like a parcel park to me? Is it related to the reverse camera I wonder 

Think n5d is a beige leather if I'm not mistaken? 
This link has numerous Audi codes which might help: 
https://www.bezwypadkowy.net/media/kunena/attachments/63/audi-option-codes.pdf

I've been having similar issues with my older A6. I've resorted to my mechanic giving me the party number then searching that part number on eBay. This method has not let me down yet. Wider your search to international sellers too as this is what I had to do. 

This shows the difference between the two. 
Pic 1 c6 
Pic 2 c7
 
 

It can't be disabled from my knowledge as it's part of the safety system. 

S3 brakes or would TT brakes fit? 

Looks like some of the pixels have gone on your LCD screen, however I think I can identify it as a bulb out. 

I'd recommend a stainless steel straight through exhaust, induction kit and then the remap. Obviously you could look at upgraded cams, manifolds etc but is it worth it?