I removed my exhaust down pipe to make it a little easier to get the rack out and access the power steering line fittings. And dropping the cradle does make a world of difference and allows you to clean all your power steering fluid and road grime off the back of the engine area. I found it rather fun to get in there and clean up many years of grime. It also helped me check my power steering lines for corrosion. Found the return line will need to be changed out in a year or two.
I don't know the percentage of Grand Prix's with the Magnasteer rack, but the difference is when you are at idle the car senses it needs more assistance to steer and some how it gives you that extra umpf. I changed one in a 2002 GTP and in my 2006 GXP, very similar on how to swap it out.
My 06 GXP had no steering assist at all when the car was at idle but when I gave the car some gas all of a sudden it would work, and there was a slow leak coming from the rack on the outside boots. I was at the auto recycling center when I came upon a 2007 Grand Prix base line model with what appeared to be a refurbished rack. It had the tag on it, was freshly painted black and in great shape, plus it was magnasteer. The car looked as it if had been near a fire due to the paint all burnt up on one side. I purchased the rack for 35 dollars and it works great. I also replaced my power steering pump since I had the motor out of the car to replace exhaust bolts (broken in the head) and rear main oil seal.
