Some friends and I invented this word some time ago, and I think it needs a wider user-base. Mainly, it's used as a superlative for our common derogatory term, "dodgy" [which I believe is akin to 'sketchy', for those USns out there, and is pretty close to shonky]. Thus a really bad used-car salesman might be fronky.

Conveniently, however - as we discovered one evening on a drive - it also fits in very well with known quotes such as "Play that fronky music white boy."

go forth, my little word, and be used!