Strange electrical issues

[Toblahoe]

Hi all, I had a strange electrical surge/short the other day which created a tonne of error codes but they cleared straight away and it hasn't come back.

So, I was driving to Manchester with a friend to pickup a car for him, it's about a 2 hour drive for me it's probably the longest continuous drive I've done in the S8 since I bought it. Car drove flawless the entire way. We got about 30 seconds from our destination and suddenly the car jerked/jumped and all the dash electrics went off. Everything suddenly lit back up and I had a red "Brakes!" warning message that went away as soon as it appeared. I turned the engine off, waited a few seconds and started it again, no warning lights or nothing so we drove down the road to our destination.

Whilst my friend was viewing this other car I used my carista (I have VCDS I just need to buy a new laptop) to scan the codes and it displayed the attached. I cleared the codes and almost everything has disappeared and not come back, the only stuff that has returned are the items I am aware off such as the wiper motor control and tweeter motors.



Transmission:
49478
P0562 - Ultrasonic sensor right for theft alarm system (G171)

ABS:
02083 - Message for Delay Request
01299 - Diagnostic Interface for Data Bus (J533)
01299 - Diagnostic Interface for Data Bus (J533)
01315 - Transmission Control Module (TCM)
01314 - Engine Control Module (ECM)

Parking brake:
00456 - Control Module for Access and Start Control (J518)
00576 - Terminal 15
01315 - Transmission Control Module (TCM)
02443 - Control head
02596 - Rear brake pads worn

Instrument cluster:
00668 - Supply Voltage Terminal 30

Radio:
00532 - Supply Voltage B+
00447 - Function Limitation due to Voltage to High
00856 - Radio Antenna

Sound system:
03017 - Motor for Tweeter front-left (V344)
03016 - Motor for Tweeter front-right (V345)
03000 - Amplifier for Digital Sound package (R184)

TV tuner:
00447 - Function Limitation due to Voltage to High

Heater & air conditioning:
00065 - Left Rear Footwell Heater (Z42)
00066 - Right Rear Footwell Heater (Z43)
00604 - Potentiometer (G113) in Positioning Motor for Air Flow Flap (V71)

Auto-leveling suspension:
01400 - Suspension Level Control

Central electronics:
00908 - Control Module for Wiper Motor
00908 - Control Module for Wiper Motor

Body/convenience system:
01134 - Alarm Horn (H12)
01134 - Alarm Horn (H12)

Driver's door:
00913 - Window Regulator Switch: Front Right (E81)

Ignition authorization:
00191 - Passenger's Door Handle Touch Sensor (G416)
00955 - Key 1

Battery regulator:
02272 - Static (Quiescent) current stage 1
02273 - Static (Quiescent) current stage 2
02276 - Static (Quiescent) current stage 5
02274 - Static (Quiescent) current stage 3
02277 - Static (Quiescent) current stage 6

Roof electronics:
00211 - Control for interior lights in the back
02138 - Activation for Right Front Interior Lights
00308 - Supply voltage engines sun roof/Rolo sun roof

Adaptive cruise control:
01316 - ABS Control Module
01315 - Transmission Control Module (TCM)


The car drove back fine, although I did drive it without radio and the head unit was turned off. And it has not done it since.

Any ideas where to start with this?