Van Halen -- Brotherly Love Is Audi This World

Eddie and Alex Van Halen came from the same womb, played in the same legendary rock band ... and now they're driving identical $120,000 silver Audi R8s.

We're told the rock star brothers purchased their new rides last Friday at Keys Audi in Los Angeles -- but for some reason, Eddie was sent alone to ink the deal.

While Eddie may be the generous type, sources say the brothers each paid for their own.

Nothing like dropping a quarter mil on some family bonding.