Perhaps if you used brand new parts. A wrecked donor car could provide a wealth of electronic components and even allow you to profit from the venture by selling off other useful parts. The other thing most people don't keep in mind is electronic components are perfectly ok when they get wet. The thing that gets you is the water shorting the circuits because most modern cars are "always on". Not all the electronic components are going to be powered up at any given time while a car is parked and some of them would be fine if given ample time to dry before attempting to start the car. If you do any long term storage of vehicles you have to do the same kind of "careful starting" that you might have to if your car gets wet. Starting a classic car thats been sitting 20 years is just as destructive as starting a highly electronic car thats just been wet.

Just like any other mechanical issue the price goes up astronomically if you run into the Mercedes dealer or greedy independant mechanic and exclaim "oh my goodness my car got flooded please help me".

My 140 is well designed with a battery mounted low in the trunk and most of its computerized components mounted high behind the dash. Its likely that water would short the battery before moving to the more expensive electronics higher up in the car. In the event that my car got flooded I would disconnect the battery and have it towed to an independant mechanic preferably in a state with low humidity to assess the problems before dooming it to the boneyard.