Does anyone know what it currently costs to enable AP1 on a used 2015 car on which the previous owner chose not to have AP1 software installed? The car has the hardware (obviously - 2015); it needs the software update to enable the functionality. I'm trying to use this cost to negotiate, as I absolutely want AP1 on the car. The Tesla website says it's $3500 to install AP functionality after delivery, but it's not clear if this is the current price for ANY car, or just for new cars ordered today without AP enabled. The cost listed to enable AP after deliver back when this car was sold in 2015 was obviously less than $3500. So which price is it? My Tesla rep I've worked with is not very responsive to questions about non-new, non-CPO cars.... understandably. Hoping someone here may have been through this already. Thanks!