With the trend for tail tidies on bikes the number plate often ends up only being bolted at the top and the rest of the plate unprotected by the mud guard and subject to full air pressure at speed. Drilling additional holes in the numberplate reduces the effect of the air pressure and therefore the stress on the top mount.
Big Kneed Al (master of the emergency stop & "stand up" comedian).
Hmmm, that could be an answer to the problem of overstressing the plate. I keep having to tighten the fixings after a long run. Perhaps a few holes would help....
I followed a group of riders back from Tyndrum to Perth last week. The tail-end bike seemed to have his number plate on a pivot. When moving, the plate was invisible (facing upwards) but then dropped down when he stopped. His bike had a tail tidy.