How to make LED’s fan out.

Here's what i'm trying to do...

I want to mount a strip of red LED's in the high mount brake light(the one sitting in the trunk). I have a 2000 Grand Am GT so the brake light sits in the top of the trunk.  But i want to make the Led's fan out in three stages.
(3) (3) (3) (2) (2) (2) (1) (1) (1) (2) (2) (2) (3) (3) (3)

#1 light up first
#2 second
#3 third,

you get the point. And so everytime i hit the brakes, they light up, relatively quickly until all lit. then they stay lit until i let go of the brakes, and so this repeats with every press of the brake pedal.  Basicaly they all light up untill the whole strip is lit up and don't turn off until i let go of the brake pedal.

I have an idea of using capacitors, one for stage (2). and a separate one for stage (3) and so as each one charges this would delay the illumination of those particular LED's. Would this work? If yes, how do i wire the capacitors? If a diagram is available, that would be great.

my concern is that using capacitors would then make the LED's stay lit for a short time after I let go of the brake, (to discharge). Which isn't bad, it just depends on how long that is.

This is kinda like making LED's scan, but i don't want it to repeat until i depress the brake pedal again.  I looked at the other topic and it seems like it would make the LED's scan repeatedly.

Another easy cheap way is getting scan pods at walmart, and replacing vulbs with them. I actually tied in myself. There cheap 6$.

Used red for brakes obviously. But since they were cheap I added some as signal warnings when I open my doors but in blue my color. So that cars ppl on bikes ect see my door open. at 6$ couldn't go wrong.

Future project is drill holes and chrome LED bezzels.