There's nothing wrong with being extra careful.
For one, yeah it would be their fault if someone hit you, but who wants to live the rest of their life with whiplash?! ...in pain, without range of motion. F@#$ that.
Two there are enough people driving like pricks already.
Of course it your choice. I'm a firm believer in highway etiquette because I think if more people would practice it we'd all be a lot better off.