No, adding the front aero kit does not give you front downforce. You can do all of the front, rear, and extension pieces, but without the rear wing added, there won't be any front downforce. It's... peculiar.
Adding the rear wing on certain cars (GT-R SPEC V, McLaren F1) gives you a positive value of front downforce (+2 and +20 for the previous cars mentioned, respectively), but expect many cars (Gallardo, 599) to have a +0 value of positive front downforce.