hmm. It's very inconsistant for me. Pressing W once will move the right hand, every W press after will not do anything. Spamming W doesn't do anything. Pressing S enough times will move the right hand again. From spamming W and pressing S every so often, I made the car move, but only by 10km/h visually.
EDIT: I found the issue. For me, the car only speeds up when the application is not in focus. I went to take a screenshot, which put the game out of focus, then the car sped up. Very weird. Not sure if this is a common issue??