Alois Ruf is a respected Porsche tuner, which helps. RUF documentation would help even more. However, body modifications from stock means that a willing buyer would have to like them. Each buyer has his own tastes, so the market would perforce be a mti smaller.,

The car still has the German Z-export plates ("Zoll") so there's no doubt it was a gray market car. It's been federalized, but has it actually been titled or registered in the USA, that is, has the entire DOT/EPA process been completed but the car not yet titled in some NY state? It's be important to know for sure for a US buyer.

If this were mine to sell, I'd definately consider asking about it on some of the good Porsche forums. Those guys'd know for sure what you had here, and have opinions on its sense of value, even though it appears to be a unique car.

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1991 560 SEC AMG, 199k <---- 300 hp 10:1 ECE euro HV ...

1995 E 420, 170k "The Red Plum" (sold)

2015 BMW 535i xdrive awd Stage 1 DINAN, 6k, <----364 hp

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2013 Jaguar XF, 20k <----340 hp Supercharged, All Wheel Drive (sold)