I did this too, Only completed it with a ferrari Enzo Stage 3.

hi i tried this challenge with an enzo but failed miserably. whereabouts in the island is the ferrari tuner shop?? ive been trying to locate it for a while but i cant seem to find it. what places is it near?? any help would be appreciated. Thanks

This will only be appreciated when attempting to complete this challenge with any other car but Ferrari Enzo. I suspect it would be difficult with Enzo too, but with 430 (tricked up though) it's a whooper.