so i can confirm that you can install sph-da01 firmware on sph-da02 decks below are the instructions.
1. update to the latest sph-da02 firmware 4.17.
2. download the sph-da01 firmware 2.64
3. extract the files from AppRadio_plus_26_264.rar, but not the appradio directory.
4. extract the CE66 folder from the sph-da01 firmware.
5. boot up the deck with the sd card. This will boot the deck to the desktop.
6. click start, programs, windows explorer. select the SD card directory. double click on the "UpgradeMPU.exe" this will install the sph-da01 firmware on the deck. when prompted,