VAG-COM-FAQ-1.12
From Ross-Tech Wiki
1.12 Can I use VAG-COM to "Flash" the chip in my ECU?
- No, we have investigated flashing, but found that there are several different methods of encryption for various VW/Audi vehicles, as well as delicate licensing issues to overcome. Therefore, we do not intend to pursue flashing any further at this time. You cannot alter boost, timing, fueling, rev limiter, or speed limiter with VAG-COM. You should contact a chiptuner if you wish to have those parameters altered.