I have a 2007 g35 coupe with 115k miles. When I reach around 45mph there is a clicking noise coming from the front of the car. Any ideas what it could be? Clicking doesn't stop unless I go under 45mph.

Checked you wheel nuts aren't loose?

Checked the wheels and they are good

Do you have a card in your spokes? (disclaimer: you have to be old to understand my sarcasm here lolololol)

Anyone have an idea of what it could be?

Motorcycle gang! Those were the days.

You may have a rock stuck in the tread of one of your tires, or possibly a nail/screw that is in the tread but not far enough to puncture it and cause a leak. I'd probably start by eliminating that as a possibility by rotating each front wheel all the way around and looking for something in the tread. Sometimes you can get a nail on the inner edge and not notice it.

Sometimes a worn wheel bearing will also make a clicking noise but usually at lower speed rather than at high speed. Best way to check that is to jack the corner of the car up and try to see if there is any lateral pay in the wheel.