Bit of a bummer mate, bonnet spray + wings and bumper blending in, to put right if your looking for perfection. There very very rarely such thing as a spot on colour match, renault are sh*tters, the cars are never the colour they were supposed to be. Im doing a full frontal and rear bumper re-spray on my clio at the moment, 6 shades for monaco blue.......bought all 6, none of them are great so blending everything, cars got original paint work aswell.
I think wet sanding unless its just been sprayed (and you did it or know theres a good depth), have a PDG (and have tested the area in many places all over) or you know the full history of the car and the panel in question, then its very high risk. So many unknowns, has it been done before?, the number of coats of clear, the quality of the clear coat used (build depth) and how evenly has it been applied.