What man can engineer, man can reverse-engineer. Dealer service departments favor replacement over repair for complex, labor-intensive jobs like transmission failures because it is far more profitable that way. It gets the customer's car out of the shop sooner and thereby frees up the tech for next job (and more jobs per tech means fewer techs needed on staff). The DCT is not unique in this regard--bring a failing wet automatic or a balky manual box and you'll almost invariably be sold a remanufactured transmission, not a repair. If history is any guide, independent specialists will someday figure out how the innards of these things are put together and offer services the dealers can't or won't. They'll never be cheap to repair, but replacement is unlikely to remain the sole option forever.