V8 Transmission problems

[CECCII@aol.com]

I have a 90 V8 with 90k mikes.  The car has recently had the timing belt
replaced(after it broke and took the top half of the engine with it).  Shortly
after the car was returned I started to have transmissin problems.  When the
car is driven around town it is usually ok but after driving on the highway
for a while, when you stop the transmission goes into a limp mode only using
third gear.  All the lights on the transmission gear indicator light up and it
can be reset by turning the car off (sometimes).  The Audi dealer has replaced
several speed sensors with no luck.  Frankly they could care less if they find
a fix.  I've been told the trans can't be rebuilt and a new one will cost more
than $8k.  Does anyone have any ideas? By the way the car is for sale.
Jim Cecchini II