To estimate the price of the 2020 Audi A6 35 TFSI (Base) with 100000 km mileage, I first considered the selling price of a similar 2020 Audi A6 45 TFSI Quattro with 79800 km, which sold for SAR 125000 on 2023-11-18. This car is a higher trim and has lower mileage, so the base model with higher mileage should be valued lower. Next, I looked at listed prices: a 2020 Audi A6 45 TFSI with 84000 km was listed for SAR 115500, and another with 80000 km was listed for SAR 137000. These listings are higher trims and have lower mileage, suggesting a lower price for the base model with higher mileage. Considering the depreciation and the condition of the car, I adjusted the price downwards. The listed prices for base models like the 2020 Audi A6 40 TFSI with 70000 km at SAR 145000 also helped in understanding the market trend, but again, the higher mileage and lower trim of the target car suggest a lower price.