Right there with you. I find that it is heightened when I am toward the depressed side. Do you have social anxiety as well as bipolar? Sometimes OCD can cause the thoughts.

I work with my T on these thoughts and they seem to come and go for me. I am having them currently. Last night I was getting into my car and I thought someone was in the bushes ready to attack. Like you, I get paranoid when I see cars driving past or if it turns with me.