the only thing I can think of is the gps knob for my car (see attached).
The 350Z uses pretty much the same knob, so I was going to head over to a local nissan dealer sometime soon to pick one up.
It wouldn't be that good for volume, but it looks like it'd be good for an idrive type of application.
I'm still open to other ideas though
and for volume, I already use this:
http://www.radioshack.com/product.as...t%5Fid=274-424
looks better in person than that pic shows.