Where have I seen something like this ?

[Peter Naulls]

Anything is possible, just look at the supply of cranks, heads, blocks etc. but if you talk to our cherished suppliers you'll discover there is a significant up-front cost to these things (even if it is machined from billet someone has to draw it /redesign it first) and very few potential customers with pockets deep enough to justify it. 

There is always a trade-off of unit cost against quantity and second-guessing how many you are going to sell in a lifetime is half the skill.

Interestingly there are more ambitious projects like this in the MG world, but then the cars are worth twice as much as ours.