Recently my 02 XJR has started dripping oil. It has apr. 150K miles (250k km) but it has always been dry as a cork.
2 months ago, I accelerated and suddenly it felt as something went wrong and smoke came fom the exhaust. Just for 1 or 2 seconds. After that it contiinued to run fine (I did a 1000 mile road trip without issues). I am not sure if the leak is related, but it would make sense.

The oil seems to be coming from somewhere above the bell house (rear side of the engine) on the right hand side of the car.
Somewhere under the throttle body and the transmission fluid pipe.
Anyone any clue what I may be looking for?

 

A common leak is from the oil gallery plug (back of the engine, above the rear crank seal) which gets loose over time. Could also be from the rear crank seal. Both require transmission removal.

Check whether the openings at the bottom of the bellhouse are oily and whether the engine oil is also spread over the transmission sump. This leak will drip on the exhaust pipes (the flexible section) and cause strong oil burning smell surrounding the car after a drive.