Used car guide

2021 Audi S6: known problems and what to check

Too few Audi S6 cars first registered in 2021 had an MOT during 2025 for reliable MOT figures. Here’s what we do know about the 2021 Audi S6, and what to check before you buy one.

54on the UK register at the end of 2025
Petrolmost common fuel (also diesel)
2known faults listed below

Known faults on the 2021 Audi S6

Reported by owners, mechanics and buying guides for this model and age. Check which engine the car has, as some apply to one engine only.

  • Electrical and infotainment faults

    All engines

    It came last of 24 executive cars in What Car?'s survey: 44% had a fault, about two-thirds electrical or infotainment (phones not connecting, flickering screens), and nearly half took over a week to fix.

    At the viewing: Connect your phone, use the screens, and check every electrical item.

    Source: What Car?: used Audi A6 (2018 on) reliability

  • Rattles and trim buzzes

    All engines

    Rattling parcel shelves and buzzing trim are reported.

    At the viewing: Drive on a rough road and listen.

    Source: What Car?: used Audi A6 (2018 on) reliability

Questions to ask the seller before buying a 2021 Audi S6

Ask before you travel to see it. A seller who knows the car will have answers, and receipts.

  1. What has been fixed under warranty, and has the software been updated?
  2. Can I see the service history and receipts for any big jobs?

What to check on a 2021 car

  • MOT history

    Check the reg below: its MOT history shows what has been failed or advised, and whether the mileage adds up.

  • Service history

    Look for regular servicing and receipts for big jobs like a cambelt or clutch.

  • Finance and write-offs

    MOT records don’t show outstanding finance or insurance write-offs. A history check does.

  • Test drive

    Listen for knocks over bumps, check every warning light goes out, and make sure the gears and brakes feel right.

Looking at an Audi S6?

Check the actual car: its own MOT history, mileage and what to ask the seller. Free, no sign-up.

Other years

Every year of the Audi S6 compared

YearMOT testsMost flagged
2026–Too new for MOT data
2025–Too new for MOT data
2024–Too new for MOT data
2023–Too new for MOT data
2022–Too few tests
2020174Tyres 22%
2019295Tyres 18%
2018–Too few tests
2017–Too few tests
2016–Too few tests
2015–Too few tests
2014–Too few tests
2013–Too few tests
2012–Too few tests
2010–Too few tests
2009–Too few tests
2008–Too few tests
2007–Too few tests
2006100Lights and electrics 28%
2003–Too few tests
2002–Too few tests
2001–Too few tests
2000–Too few tests
1997–Too few tests
1996–Too few tests
1995–Too few tests
1994–Too few tests

Where this comes from: how many are on the road is from the Department for Transport’s vehicle licensing statistics (DVLA records), counted by the year each car was first registered. Known faults are from UK buying guides, in our own words, with links. How we score