Both my FEs have flashing brake lights and I wouldn't change them for anything. I discovered a long time ago that the secret to avoiding the near misses when driving either car is to use the indicator
and perform the hand-signals as well.
Joe Doofus may not notice the red flashing light but he obviously thinks "hey that bloke's got his arm pointing out the window". In any case, performing the hand signals is a lost art that adds to the whole driving-an-old-car experience.
Jeez I hope I haven't jinxed myself. I've got to drive home in Faecal soon
cheers
RET