How do you tell when the rear wiper is on? I know, sounds like a dumb question (it's wiping, that's how), but not really because it stops wiping. Sometimes when it's just a drizzle, I can't remember if it's still on or if I turned it off, and I can't tell by the position of the switch. If I try pushing just a little forward (to test) and it's on, it sprays the rear. If I try pulling just a little forward (and it's already off), it sprays the windshield (and sometimes the headlights). Is there an indicator light somewhere?