Hard to say. Personally I feel that black on black holds it back and time of year is an issue. Without photos we cannot tell whether it has the comfort pack, front parking sensors and which wheels it has. Also service history, clutch life etc.
I should not say this as an owner but 40%+ residuals retail to retail at six years old is still amazing so perhaps this is the right price? Cars do tend to take a step change down in value once the market sees them as 'old' so perhaps a lot of potential owners are buying F type, 991, 6 series, M3/M4 etc as they are fresher cars? The next few months will tell.
