To estimate the price of the 2018 Audi S5 coupe with 54,000 km mileage, I first looked at the new car prices for the 2025 Audi S5 Standard Coupe, which starts at AED 357,000. Applying a 10% annual depreciation over 6 years (2018 to 2024), the estimated value would be around AED 178,000. Next, I reviewed the listed prices of similar cars. A 2018 Audi S5 coupe with 61,000 km is listed for AED 188,000, and another with 83,231 km is listed for AED 179,000. Considering the mileage and condition of the target car, I adjusted the price slightly lower than these listings. Additionally, a 2017 model with 71,000 km is listed for AED 159,750, which supports a lower estimate for the 2018 model. Factoring in all these data points, I arrived at a final estimate.