how do you tell if you have sport or comfort suspension? Are the XJRs all equipped with sport suspension, and XJ8s have the comfort suspension? Thank you

 

XJR's have "sport suspension" which, along with 18" wheels, makes the ride a bit stiffer than say an XJ8 with "normal" suspension and 16" wheels.

I think the VDP has a still softer suspension, the "comfort" suspension I guess.

The only thing I'm not really sure of is the electronic CATS suspension, which I think was available on the 2002 or 2003 MY cars. It may have some adjust-ability to it. My '01 doesn't have it.
Vector

 

There was a discussion about the different suspensions a while back, and apparently the US spec non-CATS XJR's have comfort springs and sport shocks (my car has this setup). Not sure which springs the CATS equipped US spec cars have though.

The springs have color swatches on them, but I can't remeber which color meant which springs...

 

Have a look on the back of your car, on the rear suspension, if you have anti roll-bar (or sway bar) with links, it's a Sport suspension.