I have the old, cassette stuck in the changer problem and after reading all the fixes, it seems that I have to pull the unit, open it up and if I am lucky, just lubricate.
I took a quick look under the carpeting and it looks like it is a fairly easy remove, although more complex than some because of the DVD player on top.

My question is, does anyone have a recommended after-market alternate unit that does not have this recurring fault, but melds seamlessly with the Jag set up?
I really don't want to have to repeatedly address this problem. My old TEAC 6 disc cassette changer, lasted 17 years without problems and eventually it was the crystals in the lasers that deteriorated from extreme age and thousands of hours of use.

I would think that your best bet is to buy an used unit and install that.

There is a guy (seamless automotive) on this forum who is scrapping an XJ and has one for sale.