Any possible recommendations for trying to capture TC and 12th scale indoors on Carpet.

The Ambient lighting seems good to the eye, but when I try to set the camera to shutter priority mode I don't seem to be gathering enough light when I use a fast enough shutter to stop motion and capture the cars without blur...

I'm using a Panasonic FZ-10...I haven't tried bracketing yet while in shutter priority..that was my next step to try....unless you can help me with some recommendations...