Forty years ago, pop stars asked: ''Where have all the flowers gone?'' Today, Everclear's Art Alexakis has a query that's just as relevant: ''Where have all the porn stars gone?'' For the answer, check the single's title, ''Volvo Driving Soccer Moms''. While his observation may seem a tad rock-star-centric, it has resonance in an age when sexploitation has been mainstreamed. It doesn't hurt that the song is as catchy as it is smirky.