OK - I know exactly what you mean.
I LOVE the ride, comfort and security of my Marquis. The thing ain't no slouch, but I was annoyed by the performance when I first got it. So, I've geared it, have a Chip on the way, am gonna get an 80mm Throtle body for it, and maybe a smaller diameter Torque converter in the future.
So rather than spend money on superficial things (I already have though), spend it on real performance parts.
Depending on how much money you have, you should be able to do ALOT of good stuff for the car. A guy from Windsor is puting in a 347 Stroker motor in his 87 Marquis. That sucker'll go! You'll find lots of ideas of things to do for the TC on
www.crownvic.org or
www.crownvic.net - don't worry about owning a TC - they are pretty much identical to the Vics, and TC owners are Very welcome on the sites.
Kevin.