Cars are made to be disposable these days in the eyes of the manufacturers, if it lasts 150K miles on the original turbo, they will be quite happy to see the car scrapped after that.

They only care about residuals for the first 5 years or so IMHO (ie long enough to see the finance off)

Cars are no longer built to be maintained, they are built not to need maintainance for an acceptable period and then after that its tough titties.