two stage led footwell lighting

Hi all, This is the idea I have. I want to add footwell lighting to my car. But I want it to be on, but not full brightness when the lights are switched on (dash lights on), and go to full brightness when a door is opened. I've read before of people using PWM for the two-stage effect for LED taillights where there was only a single dual-filment bulb. But my knowledge is very limited, and I've never worked with timers, ICs, anything like that. So unless there are cheap, ready-made PWM controllers, I'm probably not going to be able to do that. Another idea is to use a relay and resistors to supply different amounts of power to the LEDs. Or maybe I should just wire up LEDs in different circuits so that maybe only two lights up with the interior lights, and three others will turn on when the doors are open? I welcome your insights and suggestions.

You could wire a relay as follows: Pin 85 = ground Pin 86 = door trigger (+) Pin 87 = 12v from parking lights (full brightness) Pin 87a = 12v from parking lights with resistor in series (resistor value determines how much the light is dimmed) Pin 30 = lights