I have a black '81.  The paint on the flexible plastic nose has spider-webbed on me in places.  When I recently started polishing the car, the white polish/wax gets into these tiny cracks and really looks bad.  I have filled several chips and sanded/polished them back down to normal height with good results, but this just didn't seem to work well for the one spider crack I tried to fill.  Any ideas on how to eliminate the problem altogether (without a repaint) OR how to get the wax buildup out of these tiny cracks without dewaxing more than just the crack?  At least they aren't that noticeable without wax build-up in them...

Thanks! 

I just went thru this! I got to the point of a strip and spray.  It got worse with time..  I had ok results with a Meguires spray and clay for a while..

   TIME TO STRIP AND REPAINT. TAKE IT TO A BODY SHOP AND MAKE SURE THEY USE A GOOD FLEX AGENT IN THE PAINT.......REALLY NO OTHER WAY TO FIX IT CORRECTLY.

                                        REID '72 T-TOP

If you don't want to paint, a trimmed down soft bristle toothbrush will work the wax out of the cracks. But I tend to agree that it's time to sand and paint.
Scott

If you completely remove the wax, you MIGHT be able to use touch up paint to fill the crack, wet sand the touch up paint, and buff it smooth with polishing compound.

The problem is the new paint may crack due to the lack of flex agents, but maybe not.  You also need to be very careful not to rub through the original paint with the wet sand and polishing compound.  Very touchy.

I agree it's best to sand and repaint. But this may work.  I have done it before on different finishes.  Sometimes it worked.