Q: White smoke/Oil leak for Infinity 2002 I35

This is a repost, with more information. I I have an Infinity 2002 I35 V6 3.5. I've had an oil leak for about a year, and have to put a quart of oil in about once every 1.5 weeks ( daily work commute takes 30 minutes there and 30 back, 75%of which being highway @80mph). Most days (weather non a variable) white smoke comes from under my hood from both sides on the flank. It happens more during the morning drive there (before interstate) and stops by time I get to work, and also on the drive back (AFTER interstate this time) but is usually not there when I arrive at home. There is also black dirty buildup on the front of the engine block. I also have a leak, that is med brown, that is located right outside the front of the firewall (I also collected water from the air conditioner hose while trying to collect the oil leak with a small plastic bag I placed under the car, if that helps with locating where the leak is above). Good brake/coolant/etc levels though. What could cause this?

My car has 200243 miles.
My car has an automatic transmission.