Flashing brake lights are illegal, from what I understand, all across the US:
http://forums.officer.com/t80993/
Ohio revised Code:
"4513.17 Limit on number of lights.
C)(1) Flashing lights are prohibited on motor vehicles, except as a means for indicating a right or a left turn, or in the presence of a vehicular traffic hazard requiring unusual care in approaching, or overtaking or passing. "
Certain exceptions are made for various vehicles to have flashing amber lights, but no other colors. Safety vehicles and school buses can use flashing red/white, and police using blue/white.
Also, this:
"FYI those flashing brake light kits are ILLEGAL in all states because flashing brake lights violate FMVSS108"
http://www.ecfr.gov/cgi-bin/text-idx?node=se49.6.571_1108
FMVS1108 requires brake lamps and high mount brake lamps to be "steady burning".
So just be aware that what you may be installing on your vehicle may be illegal, in just about every state. And when you're driving late at night, the police are looking for *any* reason to pull you over, so they can check for drunk drivers. Also, if you get in an accident, equipment violations may open you up for risk of liability.