Volvo Repair: Turbos, mosquito fogger, volvo dealership

Question
Hello, How often does turbos go out out the 99 S80?  I was told they hardly ever go out.  and if they were working fine before they went into a shop and came out damaged.  Then something was more than likely done to interfere with there performance.  This is what I was told by the Volvo dealership.  They also mention that I would of noticed a big difference in performance and would of seen smoke long before they went out.  The I was told if someone intenially add too much oil this could damage the turbo along with other things.  I just want to know if they were going bad would there have been a sign.  I just do not believe they work fine one day and the next they are damaged with out any sign.  Especially since the Volvo dealership told me they have not replaced turbos in years on this model (99 S80)  By the way, the dealership is not who had my car when it was damaged.  It was one of those neighborhood shops... I know BIG mistake on my part.    Please help any and all information or expertise would be greatly appreciated

Answer
Michael, Get your car out of Joe's Garage.  You would know when I turbo goes bad.  It would be like a Mosquito fogger coming out of the exhaust.  You would have to add a lot of extra oil to damage that.  I agree with the dealer, they hardly ever go bad. Not sure what to tell you except go get it out of there.  Roger