Thought this was interesting. He ignores probably the most obvious thing in that with the new Corvette you get a factory warranty that goes for, what 3-5 years? And it can be serviced anywhere you can service a Malibu. Given your love of spreadsheets and analysis, Keith, I thought you'd find this interesting if you haven't seen it.
Given Rob's occupation and location I can understand why he thinks it might be acceptable to try and maintain a Ferrari as a DD, but it wouldn't fly in Wisconsin, Cincy, or Pittsburgh I assume.
This book was actually a pretty good read, one guy's year with the Ferrari he chose to try and DD. Documented the upkeep and actual costs: https://www.amazon.com/gp/product/B0077QWUBC/