Impreza Sports don't come fitted with rear anti roll bars. Most people fit turbo rear hubs as part of a rear brake disc conversion. The added bonus of this is that I think the mounting point for the droplink is on the back of them. This means that you can fit a turbo anti roll bar, which is said to make a big difference. If you didn't want the hassle of changing your rear drums to discs, Whiteline make a Sport Specific anti roll bar that comes with different mounting points to the chassis.I think they're about £150. I only know this because I was going to convert my Sport to discs, but now have a WRX, so I'm selling my sport. Hope this helps.