The suggestion of a water jet (high pressure - maybe a fire truck might work), and putting boards, or ladders (regular or the ones used on 4x4 expeditions), is your best bet.
Dig or water jet under the wheels - put boards or ladders (or those purpose built 4x4 ladders/tracks) under the wheels, at an angle so when the vehicle is pulled it rides up and lifts off the mud.
AFTER you have dug under the wheels and put the boards in, use a water jet to clear the mud under the chassis (do NOT do this bit first).
If you have a tow hitch, use that, or that discovery should have a D ring on the back (I know it has one on the front) for attaching a towing strop - use a 5T strop - so rather the strop break than the car - and attach it to something that is going to pull up and away, rather than direct from the side.
This can either be done by attaching the strop to the bucket/arm of a JCB, or in some cases I have seen a jury rigged tower, over which a winch cable runs from a secure (possibly one/several) of the trees up to a high point over a pulley then DOWN to the vehicle.
(Hope this formats ok)
pulley on tower
/ ||| \
/ ||| \
/ ||| \
<winch>____|||________________<car>
It will be a bit of work, cost a shilling or two, but less than a replacement car.
Start slow - things can break and can go wrong quickly if you did not plan.
Remember the 6 P's.
Otherwise there is in outfit in Belgium or Switzerland that will charter you a Mi-26 for about $350k
Edited to add: Remember there is a 4wd low-range fixed diff gear shift setting on these cars for a reason... people tend to forget about that in the mud (or snow)...