I recently upgraded my factory default radio on Hyundai Tucson 2005, radio model MP3-01, to an aftermarket head-unit with Bluetooth.
To remove the unit requires a special tool which is described as “Tool for removal of radio in Hyundai Terracan, equivalent to part 99260-426-0”. Below are details on the tool’s dimensions, I used 0.5mm aluminum which was easy to work with, but not very strong, it did the job though.