My relationship with Porsches is strictly platonic, however, Alfas are a whole different matter...
Small block Chevys are plentiful and offer a lot of performance for little money invested.As well we must distinguish between weight management and weight distribution (balance).
Porsches are representitive of the German mindset of engineering machines to the "brink of the unknown" (some might say to the "brink of disaster").Corvettes are the product a different philosophy, that of offering a whole lot of value (performance) for not a great deal of money. I'm not really sure if you can compare the two, they come from two different vantage points and appeal to two different markets.
As for the rear engined bike thing, you've given me an idea for a "recumbant motorcycle".Thanks.
Now you'll have to excuse me, I've got a date with a red headed Spyder.