You could wire the LEDs in batches of four ( gives about 8v for normal red LEDs) in series with a small driver transistor, and connect each of the ten drivers to a pin of the R3.
You would need 4 inputs from the light/indicator switches, and simply generate a series of output patterns with suitable delays and pwm.
I would however ( if it were legal to do this anyway ) have most of the LEDs on, and rather create a blank dot moving up the V, to give more light output - especially the brake light.