Yep keep well away from Audi or anything that DCH have their hand in parts support.
They like to consume coil packs which each cylinder has, usually once one goes causing a MISFIRE error code to begin with, then localising it via a diagnostic. One thing I have noticed though, once one coil pack dies on an Audi, the rest follow soon after. Iridium spark plugs used on the Audis also cost $125 each...
I know a lady who owns a 2007 Audi A3 1.8T wagon thats just forked out $18,000 worth of irritating repairs in the last 3 months on a car she purchased used for $135,000 6 months ago.
The problem and frequency only increases as Audi's age, to the point that the cars themselves become near worthless on the used market. I've only owned one Audi, which I owned via a company nova-ted lease from new. A fully optioned 1997 A4 2.6 V6 SE ( special edition that had the gloss timber interior trim, leather, Sunroof and factory A6 5 spoke wheels ) and had 160,000km trouble free mileage out of it, before I sold it in 2003.
Once Audi's tip over 200,000kms the problems come thick and fast, which totally make a mockery of the odometer readings that most used HK Audi cars display, if you're going through water pumps, alternators, coil packs, ABS sensor failures, egr valve,catlytic converters, oxygen sensors failures, MAF sensor failures, ZF transmission plate failures etc etc... the car has done considerably more mileage than the sub 100K reading suggests on the clock.
It costs $400 to clock a speedo in HK, and takes less than 10 minutes to rewrite the odometer EPROM, which is why majority of private sellers and used dealers ( not all just most ) cant be trusted unless they produce well documented service records that can be verified by the main agent, backing up what they say.
If the HK govt bothered to list a cars previous mileage on the Vehicle Regsitration Document during the transfer of ownership phase, HK's mythical low mileage of cars would dramatically reduce overnight.
Majority of 10 year plus old passenger cars have done well over 160,000km ~ 200,000km out here and that is a fact.