Used 2018 Audi S6 Price in the US
A used 2018 Audi S6 in the US typically lists for $25,498–$31,793, with a median asking price of $28,027 across 13 active US dealer listings (as of 2026-10-15). The cheapest one listed right now is $21,500, a 2018 Quattro Premium Plus in Quakertown, PA — below 95% of the market, so expect high mileage, a base trim or a branded title — check the vehicle history.
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typical price per yearCheapest 10 listed right now
ranked by price-
$21,5002018 Audi S6 Quattro Premium Plus118,845 mi · Quakertown, PA · Trend Auto Trader Inc.View listing → -
$23,8882018 Audi S6 Quattro Premium Plus99,746 mi · Gilroy, CA · GILROY CAR CLUB LLCView listing → -
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$25,9982018 Audi S6 Quattro Premium Plus96,900 mi · Denver, CO · Phil Long Ford of DenverView listing → -
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$29,5902018 Audi S6 Quattro Premium Plus75,839 mi · Laramie, WY · Laramie GM Auto CenterView listing →
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$29,9992018 Audi S6 Quattro Premium Plus82,901 mi · Houston, TX · Houston Auto CreditView listing → -
$31,7932018 Audi S6 Quattro Premium Plus71,484 mi · Portland, OR · Summit Motor CompanyView listing →
These are the bottom of the market, not the going rate — every one is priced below 95% of active listings. A typical used 2018 Audi S6 asks $25,498–$31,793. Cars this far under: expect high mileage, a base trim or a branded title — check the vehicle history.
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10 pinnedFAQ
How much does a used 2018 Audi S6 cost?
A used 2018 Audi S6 in the US typically lists for $25,498 to $31,793, with a median asking price of $28,027 across 13 active US dealer listings. Nine in ten are priced between $22,933 and $36,374 (as of 2026-10-15, source: UnderMarket Cars).
Is $28,000 a good price for a used 2018 Audi S6?
That sits at about the market median ($28,027) for a used 2018 Audi S6. Under $25,498 puts you in the cheapest quarter of active US listings and under $22,933 in the cheapest 5%; above $36,374 is the priciest 5% (as of 2026-10-15).
What is the cheapest used 2018 Audi S6 for sale right now?
$21,500 — a 2018 Audi S6 Quattro Premium Plus in Quakertown, PA, $6,527 under the median (as of 2026-10-15).
Are these MSRP or real asking prices?
Real asking prices from active US dealer listings, deduplicated by VIN — not manufacturer MSRP. They already reflect dealer discounts, and they exclude tax, title, registration and dealer fees.
How often are prices updated?
The listing data behind UnderMarket Cars is rebuilt from live US dealer inventory every few hours, and this used 2018 Audi S6 page is regenerated from it when it is requested. The figures on this page are from 2026-10-15.
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Prices updated 2026-10-15. Data covers active dealer listings across the USA.