The Second iteration of My Car Physics. Press Space to Cycle trough 3 Speedometers, Press X for the UI to change its color, use the arrow Keys to move around. N to turn on the Lights and V to change the Time Of Day. Press T to hide the Speed Variable on the top of the Spedometer. you can also press C to cycle trough different car models.
And if its Lagging, its called Unoptimized Car Physics for a reason.