need some help, making my own led tail lights

so i have been doing some research and thought this might help make sure im on the right track here, so in terms of leds, its basically goin to be a 10x9 led matrix(or so i think), this will be for a 67 el camino and the tail light bezel is broken into three sections, i was planning on having the upper and lower sections of the board handle the task of running lights (50% power) and then when the brakes are depressed they will fully illuminate(100% power), while the middle section will be the turn signal and sequentially light up in arrow shaped led sections. I have max7219 chips that i planned on using. Now i am not sure i can control everything/ or all the leds with just one chip per board so i was planning on breaking the tail lights up into 2 sections, the running/brake lights and then the turn signals on a totally different max7219, granted i am totally new to electronics in this depth and the use of arduino/microcontrollers.
x x x x x x x x x -running brakes

x x x x x x x x x -running/brakes

x x x x x x x x x -running/brakes

x x x x x -sequential turn signals arrow shaped. x
x x x x x
x x x x x starting every other column x x
x x x x x x
x x x x x x x
x x x x x
x x x x x x
x x x x suppose i could lose this row

x x x x x x x x x -running lights/brakes

x x x x x x x x x -running lights/brakes

x x x x x x x x x -running lights/brakes

i have ordered the led lights, the max7219chips i got 10 of them just to have for future projects, they are going to be running off the car which is 12v however it obviously fluctuates above 13.4 to 14v during operation, i am open any help or insight, i know i have to have a resistor for each column and one for each row, and that resistor size depends on supply, voltage drop, fwd voltage drop, what about transistors? and about making sure the power stays at 12v, and i am open for some help with the programming, or at least a direction as to where to go for the information, i have no problem reading and teaching myself.
as i stated earlier i was going to try to link the upper and lower rows (totalling 6, 0-2 & 13-15) to run as the running lights(50%power) and when the brakes are pressed it they would illuminate to full 100%. i was thinking of incorporating the middle section as well but i think it would look cleaner this way. i am using 5mm pirahna super bright red leds i got off ebay. i can post pics if that helps, i am pretty sure i am going to have to make a seperate board for the controllers, possibly make a ribbon or small harness that runs to a small box for the other board, and a harness from that box to the car harness, i have plenty of experience in wiring and automotive wiring. any help at this point would be greatly apprectiated thank you. i have already started to solder the upper 3 rows and the lower 3 rows together, i havent decided whether or not i am going to combine the two. I am just pushing fwd lil by lil every day, now i just need to teach myself the programming aspect for running lights, and what needs to occur to have them go full brightness, im about to start reading up on the max7219 abit more.