Buying a tuned Mk6: reversibility and emissions are the questions

A large share of these cars carried APR, Unitronic, Stratified or Cobb tunes, and the threads converge on a practical checklist: confirm the stock downpipe and cat are included, confirm the tune can be flashed back to stock (several cars had onboard map switching via the cruise control stalk), and understand your state's inspection regime - California cars needed downpipe swaps and reflashes to pass smog, at real cost, while other states passed on OBD checks alone. Sellers who kept one-shop paper trails and included reversion parts sold smoothly; missing OEM cats and live emissions codes were disclosed and absorbed into price. …