Wholesale is around  $10K for very good condition.  Mine had the check
engine & airbag lights on,  and the horn had quit working.  It also had an
oil leak and bald tires that would not pass inspection.  Despite all this
the car was in very sound mechanical condition, drove great, and probably
needed around $1500-$2000 put into it to be in good resale condition. I took
$8500 but could probably have gotten $13 - $15k  if I'd fixed everything and
replaced the tires.  I just was not wanting to do all that and then have to
sell the car as well.  But yes, one can definately get more by not going the
trade-in route.

I think most buyers of new Jags consider the time and hassle element and opt
to do the trade in.  The new XJ8L sticker price was $67,535 with premium
Alpine sound, bluetooth, and seat/steering wheel heaters (we REALLY need
those seat heaters down here in Texas).  I ended up trading my '99VDP and
writing a check for $53,500 to drive the new Jag out the dealership's door
free and clear with tax, title & license included - it was on the showroom
floor where they put the really pretty ones.   I'll be interested in seeing
how much they ask for my old VDP, which is a really great and cool looking
car.