Okay, so here is the deal. I'm missing the driver side lower rubber mount on my civic and ever since its absence my car has been driving really awkward. I mean, it shakes/jerks a lot and only at a certain mph in every gear except for fifth gear. I'd like some help or advice as to why the engine is like shaking /jerking so much... I'm thinking it is the rubber lower mount that is causing this because currently my car does not have one, lol.. My car just doesn't drive smooth anymore which feels like a go-car, lol..

 

You answered your own question. Possibly your OTHER mounts are bad on top of it.