That is my understanding for the early cars. They originally had a 16GB Class 4 SD card installed. This was 8 - 9 years ago, a long time in technology. Doubling the memory should do nicely, and getting a fast endurance SD card should speed things up. The MCU1 may not be able to address more than 32GB, and I doubt if it needs more than that. I can't find where I found the 32GB, but I know others have installed this much successfully. More really isn't going to help that MCU. It is too slow, in my opinion.