I was looking at these some time back for use on competition cars too.
I never did buy any and from what I have seen of them they seemed to be more for the bosozoku type subculture cars.
Its the sort of thing you would really need to buy and then see what you could do with them.
http://www.1999.co.jp/search_e.asp?Typ1_c=112&scope=0&scope2=0&itkey=fujimi+over+fender+set