HI mines an April '17 build and I had purchased FSD when it was in that 2K "sale" after taking ownership. you will have to shell out the $2500 for the MCU2, good news is HDW3 board upgrade comes "free" with FSD if you had bought it but you really need MCU2 to get the most out of it . I know some folks who kept MCU1 but did the HDW 3 upgrade. you run the risk of our cars having the Dreaded MCU 1 . failure ( see the other threads on this) . I would recommend doing the MCU2 and HDW3 together. you wont regret it if you plan on using AP, NOA, and FSD when they roll out the latest stuff. I have it and it essentially made mine as good as a 2020 car ( less the battery and better efficiency with the motors and a few other thngs). other wise it feel s and visualizes like new!. did I mention the browser actually works and you get wifiG ( worth it right there)