I picked mine up at a parts store in town. ~$40 or so. Summit Racing and Jegs sell them as well.
Under the car, directly in front of the subframe (might be behind), you will see two roughly 3/8" steel lines. Follow the one that exits the bottom passenger side of the radiator and mark it so you wont have to look later. That will be the one you will splice into. I bought the biggest cooler that would fit, it was once size smaller then the largest they had on the shelf (too big you will hit the crash bar/structural braces). Loosen the A/C condenser enough so you will be able to get your hand up in there enough to push the little plastic clips on. Feed the clips through the cooler/foam insulators/condensor, snap the other side into place and cut off the excess. Tighten the condenser back up, cut the line with an actual pipe cutter, not a hacksaw. Flare those two cuts (I had to bend the tubing somewhat) and install the rubber hose to the cooler.
It sounds time consuming but its actually not too bad. Some people will say that you should splice the cooler in *before* the radiator, that it will cool better. At any speed above 50 mph, the setup I had would have me at 170-190 degrees, which was enough to make me happy.
If you head into the transaxle forum, you will be able to find a slightly better how-to. To help save you some time, the cooler I had on the Contour when it was still an ATX was 7" tall x 11" wide x 3/4" thick.
My setup also included a remote transmission filter as well. That was mounted behind the bumper cover, in front of the driver's front tire.