Premcar announce Barra upgrade is coming.

[4Vman]

Quite possibly. That said, I would place a value on having a 'Premcar' enhanced car over what any local workshop would provide. For starters, it would be ADR and emissions compliant and designed holistically to work with all the other elements of the car. That is worth something more than a sum of optional parts. The problem is, I would be investing in a car that is not collectible and still depreciating in value. If I threw the kitchen sink at it and did wheels, brakes, suspension, rear end architecture, turbo, intercooler, mapping, head, intake, exhaust etc..that would cost $45k+ on a car that is worth around $15-20k now. I cant not see the car being worth even half that in years to come.

This makes me think an F6 or Sprint may in fact be a better base proposition.

A F6 is a better base to start from than any other T6 product outside of Sprint 6 which would be the best of all.

Without wanting to over generalize, that OEM value proposition is an easier scenario to "sell" to a GT/Miami owner than the traditional T6 owner.