Used 2020 Mercedes-Benz GLS for Sale nearSaint Louis, MO

How much does the 2020 Mercedes-Benz GLS cost?

Prices have softened 14.43% compared to this time last year, making it a favorable time to shop this model year.

There are 762 listings available, which suggests a healthy amount of inventory to compare.

Is the 2020 Mercedes-Benz GLS a good car?

Yes — 5/5. The 2020 Mercedes-Benz GLS is the roomiest vehicle in Mercedes-Benz’s lineup, with three rows of seating for six or seven people and up to 94 cubic feet of cargo space. It also blends luxury-sedan comfort with SUV utility, making it a strong fit if you want family-friendly space without giving up a premium feel. For 2020, it added a curvier design, a wider cabin display setup, a longer wheelbase, and more comfort and safety features. The market also shows 37.3% of listings are priced as good or great deals, which gives you some room to shop selectively.

Is the 2020 Mercedes-Benz GLS reliable?

Owners rate it 5/5, a strong signal of long-term satisfaction.

The 2020 GLS also benefits from a more efficient powertrain than before, with Mercedes citing improved fuel economy over the prior model year. Its standard equipment and safety technology are generous, which can help reduce day-to-day ownership friction. For used buyers, the main long-term risk is that a luxury SUV with this much technology and complexity can be costly if prior maintenance was inconsistent.

What should I look for when buying a used 2020 Mercedes-Benz GLS?

At 74.7% accident-free, a meaningful share of listings has prior incidents — history verification is especially important.

Start with a vehicle history report so you can confirm accident records, title status, and service history before you go any further. Then prioritize a pre-purchase inspection, especially for the third row, touch-sensitive controls, and any signs of wear from heavy family use. Focus on overall condition and how well the luxury features, seating mechanisms, and electronics work in real-world use.

Is now a good time to buy a used 2020 Mercedes-Benz GLS?

This is a moderate market, so you can be selective without expecting every listing to be a bargain.

• Deal availability: 37.3% of listings are priced as good or great deals.
• Inventory: There are 762 listings available.
• Price trend: Prices have softened 14.43% compared with last year.
• Clean inventory: 74.7% of listings are accident-free.

If you find a listing below $32,357, that's toward the low end of the year-round range and worth acting on quickly.

What is the 2020 Mercedes-Benz GLS's resale value?

The current average of $32,357 sits slightly below last year's $37,814.

That decline suggests the market has already adjusted downward, which can help you buy at a more favorable entry point today. For a future seller, it also means resale value may depend heavily on condition, mileage, and how well the vehicle has been maintained. Well-kept examples should stand out more clearly if the broader market stays soft.

Vehicles with strong owner satisfaction ratings, like this model year's 5/5, tend to retain buyer demand, which supports resale value over time.

Should I buy a 2020 Mercedes-Benz GLS or consider a different year?

If you're weighing the 2020 against nearby model years, here's how to think about it:

Choose the 2020 if:

• 37.3% of listings are priced as good or great deals.
• At 74.7% accident-free, a meaningful share of listings has prior incidents — history verification is especially important.
• Price trend: Prices have softened 14.43% compared with last year.
• Owners rate it 5/5 — a strong satisfaction signal.

Consider the 2021 if:

• At $46,213, the 2021 costs more than the current year's $32,357 average.
• It brings a more luxury-first character with multiple powertrain options and a stronger flagship feel.

The bottom line: If you want the better value, the 2020 is the smarter starting point because it combines strong space, luxury, and a lower average price. If you’re willing to pay more for a newer model-year experience and a more upscale positioning, the 2021 is the better secondary path.

These recommendations are based on CarGurus' proprietary market data from September 29, 2026, CarGurus experts' opinions, and generative AI.