Originally Posted by CDSmith

Actually that's "what's the difference between a cop car and a porcupine"

a: "with a porcupine the pricks are on the OUTside"



...and it's as old as dirt.



Minte, all I can think of is

ETMYDST

not very original, sorry.

How about EMDIFTY --- "even my dust is faster than you"