Bug wipers are allowed in US contests in all classes except sports and
PW5. (Just bring up the rules from ssa or sra website and search for
"bug wiper". It took me less than 2 minutes.) Not many pilots use them
in the US, I presume because most US contest flying is a lot less buggy
than in Europe. Or maybe we're all following a nice implicit bargain
"if nobody else bothers with them I won't add them either" to keep
things a bit simpler for once.

John Cochrane BB