Back in February, this thirtysomething Animal House did better at the box office than it really deserved. The comic idea was far superior to its execution. Still, Vince Vaughn, Luke Wilson and especially Will Ferrell do wonders with their underwritten roles as former college buds -- two now married -- who use a rental house near campus to revert to their frat-boy days, including brewskis, topless wrestling contests and streaking (another indecent-exposure op for Ferrell -- what's with this…