The Yellow Mini Cooper

Today I was on my way home from work. The road i take, Jalan Masjid Negeri was, as usual, jammed. I was stopped at a traffic light, so i took a look out the window at the car next to me ( Yellow mini cooper wei... how can i not look??). Anyways, the road was slightly inclined down and as i stared out the window, i noticed the yellow mini cooper slide past me. And the first thing i thought was how on earth is the mini cooper sliding backwards when the road slopes down.
Then I felt a little funny.

It took a while before i realised my car was sliding forward.