High Mileage Engine Problems

My car is, in fact, an A100 avant Quattro with the 2.8 litre V6 petrol engine, but is the version which became the first A6 Quattro avant,. It has been entirely Audi serviced all its 150,000 miles; last sunday it died.
For a long time there has been an overheating problem when travelling slowly, blamed on faulty radiator temperature sensor switches. Changing it did not cure the problem. The car is still in the garage waiting form a complete dismantling of one side of the V6, where there is very poor compression. The cam-shaft drive belt tensioner pulley has disintigrated, and the timing shot - whether this was a cause or effect is not known at the moment. The Water pump seems to have disintigrated.
Has anybody else seen this type of situation. I love my car, and have been completely satisfied with it: no problems until now. What is in store???????