To estimate the price of the 2020 Audi A6 45 TFSI Quattro I4 2.0L Turbocharged with 125000 km mileage, I first looked at the selling price of a similar car with 79800 km mileage sold for SAR 125000 on 2023-11-18. Given the higher mileage of the target car, I adjusted the price downwards. Next, I considered the listed prices of similar cars: one with 84000 km listed for SAR 115500, another with 80000 km listed for SAR 137000, and another with 79800 km listed for SAR 125000. These listings suggest a range of SAR 115500 to SAR 137000. Given the higher mileage of the target car, I adjusted the price downwards further. Finally, I considered the depreciation logic, assuming a 10% depreciation per year from the new car price, but since no new car price was provided, I relied more on the actual selling and listed prices. Considering all these factors, I arrived at the final estimate.