take your keyfob, and lock/unlock the doors...i've tried that before, but with such long shutter speeds they tend to get blown out and blurry looking. the best solution is to have someone in the car turn them on for a few seconds, but i didnt have a second person.
unfortunately my lights dont blink when i arm/disarm, just the horn honk. i could set the camera for a 10sec timer and run to the car before the shutter opens, then count till it closes. its just kind of a grandma when i'm doing a bunch of exposures.