I owned a BMW 5 years before the Audi and used INPA and Carly.
The INPA cable is useless on Audi LOL.
The BMW Carly was very user friendly so I looked into that 1st..unforetunately Carly only invested heavily on BMW and so features on Carly Audi is no comparison. With Carly you cant even do a battery register on Audi... maybe they will update in future.
The VCDS is the best tool for the advance user and but quiet a expensive investment but is the best.
I went for the Obdeleven Pro option. It was about £60 direct for their website. It can do enough for the average DIY person like myself..maybe not enough for a advance DIY person though
I replaced the heater blower today.... But now there is an air bag light on....not sure if I reconnected the air bag wire to the parcel shelf or whether all of the crap she had on passenger floor had dislodged a cable when I was shuffling on floor to get blower in...
Looks like I'll have to get an obd tool now to reset the light.. But at least she now has a warm car!!