Generally it's ok. But if there's no specific destination, i would suggest you delete that last "去".

Both correct. Yet, 我常（常）坐车 means someone drives me often. 我常（常）坐车去 means the destination is mentioned in a previous sentence and you are just telling another person how you go there normally, or you can add the destination at the end of this sentence. (ex. 我常坐车去公司）

So, where are you going? When people use 去, it always follow the destination.

对的