One problem I have read of, is an owner having severe computer problems requiring a new computer module. You cannot just go to the salvage yard and plug a different one into your vehicle. Each vehicle has a uniqueness, different options, etc. The computer has to be 'flashed' at, AFAIK, a dealer shop to make it work for your vehicle. If I am wrong, hopefully someone knowledgable will explain it to us. Of course there are 'performance chips' available in the aftermarket. Are these a simple 'plug&play'?
Is there perhaps any sort of diagnostic computer unit for the small shop or home enthusiast allowing one to 'flash' or reprogram their vehicle's computer brain?