Mike,
If you have more details, it would help a lot. Was the car LHD or RHD? When you say "grey", was it light, medium or dark? You state that it had metal flares, but the GT5 cars didn't — they are fiberglass. So were the flares added after by someone, or was the car actually a GT5-S? The factory never added turbos (that I am aware of), but many guys have modified the cars, although very few have done twin turbos. What colour was the interior? Are there any other details you can provide such as what model year it was?
If you have a modern smart-phone, you can probably take a half-decent shot of your photo if getting access to a scanner isn't easy.
But taking a quick stab in the dark, here is a grey, steel-fendered GT5-S with a supercharger. Way less than 800 HP, no bucket seats and painted in California not Italy. But it is in Australia now.
Mark
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