I got a new Impreza Outback Wagon w/ factory bars and the Yakima/Sub bike rack. I think its the raptor, arms clamp to the downtube, ft wheel stays on. Its noisy, gas mileage goes way down, and I have a bike that ranges from 36-41 lbs, I drive a LOT slower around corners with it up top. I've gone to just putting it in the back of the car when I can instead of using the rack.
I think, and it seems most people in the dh/fr forums agree that a Thule T2 hitch rack is the way to go. There is a recent bike rack thread there. I can get a 1 1/4" drawtite hitch for under $100 that bolts onto my car, the rack is about $300 on sale. They are good for bikes up to 60 lbs. My bar/rack combo may be more flexy than most, I'd bet a King Cobra with Yakima x-bars and towers would be a lot better than what I have, but the noise, gas mileage, exposure to dirt and bugs, and danger of driving under something too low and doing thousands of $$$ of damage to your bike/car are still issues.