It almost sounds like you feel people will form a bad opinion of you if you ride to work. You probably had an experience that made you feel that way? Personally, my experience with co-workers is that at first they seem mildly interested, but after a while they just accept that I'm the guy who rides a bike to work. Sometimes they even kind of brag about me to new people.
Anyway, if being incognito is the most important thing to you, park in the trees. Or even park by a different building. But I think it's only a matter of time before somebody sees you. I would ask the security department where they think I should lock. I did that where I work. They even took me inside their office and showed me the camera coverage and helped me figure out a good location.