I took couple 03 -04 SL500 recently as well as one 00 E55 AMG as weather gets colder here in Chicago in my supercharged Accord V6.

SL500 - 1/4 mile range from 14.4 to 14.6 with trap speed 99mph. Your auto G35 should be in the same range so I'd say its drivers race. You could've been neck to neck with him all the time if you'd launch like crazy you could've taken him but not much. What you need is intake, headers, exhaust (i/h/e) , and light rims and you should be close to 14 flat.