If they think I've been drinking, and they won't believe me, I request a breathalyser since I know I don't drink. This works great in WA State because it gives me the opportunity to prove I'm sober.
It does not work well in Oregon though. Because in Oregon they don't have a breathalyser in their car. In Oregon, the breathalyser is at the police station or county jail. So no breathalyser possible until AFTER you're arrested. This means in Oregon I cannot prove I'm sober because I'm to handicapped to take a physical sobriety test. I can't walk heel to toe or stand on one foot, etc. Oregon law sucks.