I don't know what yor camera will allow you to do, so I cant tell you exactly what to do.
In pitch dark, you are going to have to add light, whether you do it with a flash or with a "bulb" light source. I would avoid that, since any light source you would be small -- in a professional shoot, one would use huge light banks. A small flash or flod light will be too harsh.
If I were shooting my TD with the goal of seeing the TD, and still seeing the glow of the lights, I would do just what I did on the MX-5 photo attached below.
I set up my camera on a tripod, and got the car all set and ready to shoot, and then waited until the sun was setting. Then, with the car lights on, I started taking a shot every minute or two untill the sunlight was pretty much gone.
Then, I took the images into photoshop, found the exposure that best acheived what I wanted to acheive, and worked on it in Photoshop till I got it just right.
You can do the same thing, assuming your camera's "brain" doesn't take over and try to "lighten" the shot which will blow out the highlights in the photo.
If you know someone with a digital SLR, you will have a lot more control over your exposures with one of those.
BTW, I mentioned a pro shoot using huge light banks. By waiting until the sun just droped below the horizon, I had the world's largest light bank at my disposal to shoot this car.
When the sun is above the horizon, IT is the light source, and although the sun is enormous, it is also a gazillion miles away, making it a small light source relative to us here on earth. You can easily block the sun from your view with your outstretched hand.
As a small light source, the sun is "harsh" lighting, that creates glaring highlights and hard shodows. The sky, on the otherhand, provides very soft light as it reflects and diffuses the suns light.
And as the sun goes lower beneath the horizon, it is like having a dimmer on your huge light bank, and at some moment, the light from the sky will be in perfect balance with the glow of your TD lights, and at that moment, you have your shot.
CD