An icon has appeared on the dashboard panel that has an open-at-the-bottom circle, a downwards ! exclamation mark and a triangle. Besides, the word BRAKES like came on at the same time. What does it all mean/ This is all in a 2011 Z3 Roadster. I will appreciate your answer.

Yellow circle, with triangle and exclamation mark – The Electronic Stability Program (ESP) dashboard light flashes if the ESP or traction control is activated whilst driving. If ESP or traction control has been switched off, it will light up continuously. If ESP or traction control is not turned off and the warning light illuminates continuously, it indicates a problem and malfunction with either ESP or traction control.

If the circle is not continuous and has an arrowhead at the bottom, it has to do with the stability control system. See the link for a description and meaning. I recommend watching the short video near the bottom of the page.
http://dashboardsymbols.com/2010/10/dynamic-stability-control

I recently purchased a 2005 Z4 (76,000 miles), and I just experienced the same thing (beep, then yellow Brake and Triangle Light (w/exclamation point/semicircle appears on dashboard). It is intermittent. Did you ever find a solution?

if its appearing on the lhs off the dash its just when your tyres are losing grip whith the road surface.

Hi, The exclamation point in triangle blinking is the "Emergency Blinker" This blinker turns on all all of the turn signal lamps at all four corners of the car. Left and Right, Front and Back. The triangle represents the European symbol for roadside emergencies. In fact on European Mercedes and other cars there is a triangle shaped reflector you can put behind the car so that other drivers know you have an emergency. THAT TRIANGLE ON YOUR DASHBOARD IS A BUTTON. PUSH IT ONCE. THE BLINKING SHOULD STOP. If you have a roadside emergency, and are broken down by the side of the rode. Push the Red Triangle and your lights will blink on and off ouTside to say, in effect "help".
Hope this helps.
Best,
Mark

you have a brake fault

think this means you have a light out somewhere ,or the brake fluid is low ,even the windscreen washer level could cause this

That should be your handbrake light

Could be the motor-management-warning light, but I guess it's the break-warning light. There might be too little breaking-fluid left in the lines ... A boardcomputer-readout should clarify this.

Otherwise, try parking on an ascending road with the nose pointing up, hit the hand-break and wait like 2 minutes; the light should come on. You might wanna retry it with the car's nose pointing downwards as well ... If so, definitely the breaking-fluid, otherwise probably not ;)

In any case - flashing warning light are never ok, so when you see it again and you're sure it's not just the ABS/ESP warning light, go and have your boardcomputer read-out, since it should contain useful errorcodes ..