Luxury cars Cadillac, Lincoln, and Lexus have then, as warning devises. If you want to change lanes to the left and there is a car there, the seat vibrates on the left, or right depending on which side is obstructed. The back vibrates if your backing up and there is something in your path. It also vibrates if it appears you are drowsy. I guess this would be a real trip if you did donuts in a parking lot!
The vibrating car seat has yet not been invented, although it was announced to be launched in 2013. This new technology by General Motors was announced back in February 2012 for the Cadillac. The technology involves vibration of the seat and this provides tactile feedback to help keep the driver alert.