John---There are a lot of expensive solutions in trying to resolve some
of the strange noises our cars can make. My suggestion is a cheap one.
IF you're running with the trim rings around each wheel, try taking them
off, one at a time, and drive by this "wall" again. These things will
definitely "tick-tick-tick" as each revolution of a tire can act on the
inside cleats that hold the trim ring on, especially if the friction
isn't evenly distributed. If this is your case, solutions can vary, from
a thorough cleaning of ring and wheel, to repainting the wheel, to
truing up the ring cleats.