Just bought a 2004 A8L with 180k miles got it for 1750. Think I did pretty good. Has its issues of course.

Something i want to get fixed quickly is the heater. Car heats up perfectly, only the driver vent comes out hot. The rest are ice cold. Sometimes the driver goes cold as well. What's going on here?

Also first day I had it the mmi worked great. Next day it pulls up to the start screen and shuts off. Won't go past it.

 

Hello,

My names tanner! I help manage 9th Street Auto out of Arkansas and we ship parts all over the country. We currently have two 2004 Audi A8's that have been completely tore down and are ready to part out. If you need any specific parts don't hesitate to contact me. ebay@9thstreetautomotive.com.

Thank You

 

Hello, it could be the heater valve block assembly under the windscreen wiper area. Looks like an octopus of pipes around a metal part that is valves and pumps.
The best thing for both of your issues is a VCDS (vagcom) scan, save and clear the fault codes and see which ones come back and post them here (full scan)
The MMI shuts down like that for a myriad of problems such as stuck button, drink ingress, fuse blown or MOST bus fibre break due to fault on any of several interconnected things such as Navigation or BT phone, CD player etc..