In my situation with my A6, swapping the engine also requires the matching ECU and injection pump and then it being coded to the instrument cluster. I'd suspect you'd need something similar
Hmm in that case I'd recommend you work through each fault.
Also how old is the battery. A failing battery can throw up all sorts of electrical gremlins
They could be historic. You've done the right thing making a note of them.
My advice would now be to clear the codes, drive the car a couple of days and see which, if any fault codes return.
This any good?
https://www.ebay.co.uk/itm/403742325051?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=8u2oe99jtbe&sssrc=4429486&ssuid=IE07kO4STZy&var=&widget_ver=artemis&media=COPY
Have you had a diagnostic check to see if any fault codes flag up?
How old is the battery? A failing battery can cause all sorts of electrical gremlins.
Speak to Audi customer services. If it was listed at the time of order and you've not been notified otherwise then they should do something. Especially under consumer law.
They will fit, but you'll need wings, bonnet, lights, bumper. And maybe a slight modification to the slam panel. Also if you go from halogen lights to xenon's you'll need additional modules, wiring harnesses ect.
Doing a great job so far. Have a look to see if carpets are wet as Audi's of this era had a computer on the passenger floor called a CCM. If it gets wet it can cause electrical gremlins