I have a 2000 Crown victoria LX I've recently purchased. When going over dips it used to dip more on my right rear. Now it makes my car "twist" when I go over dips and feels not safe to me. What is it I need?
Look for oil seeping from shock absorbers.
Check the sway bar links in the front. They can often break and cause excessive leaning in turns.
I just did a rebuild on my 2004 Vic two weeks ago. I thought I had a steering problem. Turned out the factory-original (16 year old) bushings were shot and missing chunks from the rear upper and lower trailing arms and from the Watts link; this allowed the axle to wiggle in every direction and made the car feel unstable in turns, dips and straight line. Front sway bar links were also worn out and a very common part to fail. I also put on new shocks. It drives like new now. I did it all at my home garage with just a jack and two jack stands and hand tools (including a torque wrench) in about 8 hours going slow; I learned from Scotty to search YouTube and saw how to do the job easily. The parts (even Motorcraft) for this car were pretty cheap so I saved a ton in labor costs. The only thing I paid a shop to do was a wheel alignment afterwards to center the steering to the axle with the new parts. Also check out http://www.crownvic.net forums. Good luck!!
