My car had a wobble now a loud violent thumping?

So these cars have special fluids that can break down and not allow the clutch discs inside the transferase and rear differential to slip, instead they chatter which can give you that shudder sensation. If these fluids had not been changed at 150,000 this is where I would start. Any warning lights on? Here is how to change the fluid out also, make sure you use Porsche fluids only! This is important.

Fluid Types


Approved oils for transfer box Z48/00 (S) and Z48/50 (Turbo) as of January 2003.

Type .................... Esso ATF LT 71141

Porsche Part No. .................... 000 043 205 09

Note: Esso ATF LT 71141 is red in color. The factory-fill oil comes from a different manufacturer and is blue in color.
Capacities


Transfer Case Fluid Capacity

New Filling .................... 0.85 liters

Change Quantity .................... 0.75 liters


Approved oils for front-axle final drive (all-wheel drive) V48/00 (S) and V48/50 (Turbo), rear-axle final drive H48/00 (S) and V48/50 (Turbo) as of January 2003

Front-axle final drive

Type .................... Burmah SAF-AG4

Porsche Part No. .................... 000 043 205 30

Rear-axle final drive (w/o differential lock)

Type .................... Burmah SAF-AG4

Porsche Part No. .................... 000 043 205 30

Capacities


Rear-Axle Final Drive

Filling Capacity

New Fill .................... approx: 1.4 liter (1.5 quarts)

Change .................... approx: 1.4 liter (1.5 quarts)


Check out the images (below). Please let us know what happens.

This is as bad as it got, not driving it anymore until i change those.

Yep, that is what I would do. It might be a good idea to run a CAN scan. You can get a CAN scanner (Controller Area Network) which will work on most cars from Amazon.

Here is a video to show you how:

https://youtu.be/u-4syLc-ifQ

Please go over this guide and get back to us.