A while ago while driving on the highway, I hit something. At that time, I thought it was just a small rock or something, so I just continue driving. Just now when I checked my rear left tyre, there is a small piece of rubber missing from the sidewall (see pic below). So I would like to ask you guys, especially sifoo vr2turbo, is it ok to continue using this tyre, or should I replace it? Thanks...