Run the resistors in parallel to the LEDs. Depending on where you are putting the LEDS will determine which type of resistor you will need (On my mkv anyways). First,I would try using a normal 100 ohm resistor. If that doesn't work, use a load resistor.
My footwells and interior lights only needed a normal 100 ohm resistor but things like tail light bulbs would probably need a load resistor.