sb, We use almost the exact same type of cabinet installs. Where did you find the black, slim toe kick vent? I need that! we have been using one that is a little to big if I don't get to meet the cabinet guy before he builds.

 Paul posted in another thread that this is a printer feed slot.
If I remember correctly Woodworker's or the likes was his source.
[Link: woodworker.com]
If memory serves right, he posted pictures of how he uses a router and all.

Paul, let me know about the felt you use on the bottom.

Thanks for the info. Pretty cool. I will order some

Mario linked the right one.  It's a paper grommet from the days of dot matrix printers with paper feeds where you left a big box of paper onthe floor under the table. 



Middle Atlantic has an optional slider for the bottom that you can order.  The SnapAV rack comes with one.  You can also stick on the fuzzy side of wide velcro strips to hlep them slide.

A little additional info that you guys might want to know. If you decide to use a slide out cabinet rack from snap, Interesting enough, you want to use the cabinet slide out base with a standard rack( not the cabinet rack) for better clearance when rack is slid out fully. This is the way Snap recommends doing this. The standard rack can handle more weight as well.