Given the lack of specific data points such as actual selling prices, offers accepted, or listed prices of similar cars, I will use the depreciation logic based on the new car price. Assuming a new 2011 Porsche Panamera 4 V6 3.6L Standard had an approximate price of 400,000 AED, and considering a depreciation rate of 10% per year, the car would depreciate significantly over 13 years. The formula for depreciation is: Depreciated Value = Initial Value * (1 - Depreciation Rate)^Number of Years. Therefore, the estimated value is 400,000 * (0.9)^13. Additionally, considering the car's bad condition and high mileage, I would further reduce the estimated value by 20% to account for these factors.