Fobra

its related.... kinda.

Like he said, back to the point. You have to check your state laws, but im pretty sure its legal to have and illegal to use everywhere. Having the bottle hooked up is only probable cause to believe it was used, absent some other statute... they still have to prove you used it (good luck with that). The end all point is that you can refuse the search and you should, exercising your rights is the best way to not only protect yourself, but everybody else also.