For $25,000 I'd buy the WRX and take the rest of the money from buying the other (2) cars and mod it out and make it REAL fast. The commercial says that the WRX is already faster than the S4 from 0-60mph

If money isn't an issue though the S4 has that level of re-finement that the WRX can't match, so I guess its what you want in a car