2 fixes I did, and saved $2000 for $7 fix !
vehicle: 2004 A8L with 150KKm.
1st issue: check engine light on. Stealership ays just keep driving otherwise we will have to trouble shoot at $125 and hour. We will start with replacing O2 sensors........ Radar goes up. Stealership, and you cant pull codes and identify ??? Went to a Volks aftermarket tuning speacialist....same BS. went to a tinker kind of Audi guy, same thing. They're all 'businessmen'. cost would have been in $800 - $1200 range.
bought a $40 check engine code reader.
lean codes p0171 and p0174 came up.
first and easiest and cheapest starting point = cleam maf sensore and clean air filter.
result = check engine light off now for 1200km's.
cost = $7 !
next issue I solved.
Truck lid motor not engaging and locking trunck.
All the 'repair people' or as I know them 'parts changers' suggested change motor and hinges and lube + labour = $700
solution and fix.
WD-40 on all hinges and lock.
followed by graphite lubricant after wipedown.
immediate result = trunk locks, trunk motor works fine.