At least Saab didn't use a pair of Phillips head screws like Honda did on their older cars. I've always had good luck getting the Saab ones out with an impact driver, but the Phillips screws strip too easily for even that. I always thought it was weird that the rotors on my parent's Pontiac Grand Prix weren't held on by anything but the wheel, but it worked, and there were never any issues getting the rotors off. Of course that car also had studs, which allowed the rotor to sit on the hub a little more securely while the wheels were put back on.