If it was a CL600 with the 500+ bhp bi-turbo V12, then it also weights 4900 lb without occupants... so, you'd probably be neck-and-neck since that's pretty much the same power-to-weight ratio as the Z.
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'10 PW 370Z 7AT - wife's car - Project Raspberry Cheesecake
'08 Evo X - built motor+trans | BB-X @ 32 psi | CH3OH | self-built+tuned - ??? WHP
'01 Galant V6 - built motor | GT35R | self-built+tuned - 550+ WHP (retired) |