Oh that's going in.
!!!!!!!!Hazard Lights!!!!!!!!
General information: Your vehicle is equipped with hazard lights to let other driver's know your car is either stopped in the way, or is about to be because a wheel feels like it is going to fall off and you're making your way over to stop. They are not for "hazardous road conditions" but rather "hazardous vehicular conditions.
What you should do: When in the rain, turn on your head and tail lights. THERE! Now you're visible, no more action needed. If you ride the brakes and take it slow, which you will probably doing in a heavy downpour traffic conditions, then the bright third brake light and extra bright tail lights are showing other drivers where you are PLENTY well. If your car stops in the middle of the road, or partially in a flowing lane of traffic, or inthe middle of a parking lot but not in a space, and you feel it is in the way, THEN turn on your hazard lights. If you lose all brake pedal feel, or if your steering locks up, now is a good time to use your hazards as well.
What you should NEVER do: Unfortunately I can't say you should never drive with them on, because for some ungodly reason, the book issued by the DMV actually recommends you put your hazard lights on in the rain. I just recommend sticking to your usual lights though. There isn't really anything you should NEVER do, but for everyone's sake, just pretend your hazard lights are forbidden in any situation that is unlike the one above in the "what you should do" section.
Why it is important: It's unnecessary when a static light makes you visible already. Also driving in the rain requires concentration, a blinking light is DISTRACTING as hell! driver'shave enough to worry about in a heavy downpour. Also, if you're turning or merging lanes, the hazard lights treat your turn signals as if they don't exist so when you merge into me with your hazard lights on, I'm going to have to say I don't see how it couldn't have been your fault.