Circular Lights for Vehicle

I purchased some aftermarket LED lights for my car a couple years back, the cheap Chinese construction has caused me to rebuild them with new LEDs and/or voltage regulators. While in the process of rebuilding them I always thought it would be cool if they had a certain effect instead of just on/off. I understand that making them blink a couple times before complete on would require a controller and as good as that would be for getting peoples attention like most of the other newer cars on the road today It's still pretty plain. I've been working on a circuit that I made back in middle school but cannot for the life of me remember how I did it. Back then it was just a straight line of LEDs turning on one after the other, but in this case it would be the same concept but around a circle going clockwise(counter clockwise for the opposing/passenger side). Looking at the circuit in my head I know it was some sort of combination of transistors and a capacitor with each transistor that would fill and then activate said transistor using the capacitor as a timer of sorts, each one of these circuits would be used to slowly(or quickly depending on the capacitor) light up each LED in tandem until they all turned on. Remove current and they slowly die in tandem as well. Like I said I have no idea how I did it and I can't seem to replicate it. If anyone has an idea as to how I did this or maybe even a better way (besides a microcontroller) please help. The reason why I don't want to use a microcontroller is each LED will need a logical on wire and the amount of LED's I need to use(20+) it would be alot of wiring vs a series circuit.