...because they like my car!!
Found this passage in a review of the 99 Ultra:
Originally Posted by Edmunds.com
Driving the Park Avenue Ultra, with its 3800 Series II Supercharged V6 engine, was pure bliss. The ride still felt floaty over any kind of bump, but you couldn't ask for a smoother, quieter machine for cruising on the highway. When the supercharger kicks in, it'* all you can do to keep from gripping the steering wheel with both hands, slinking down in your seat and screaming "supercharger!" at the top of your lungs as the two-ton mass of metal seems to attempt air travel. This thrill clinched it: the Park Avenue is definitely not just for Mom anymore.