Possible to get a subtree agenda view?

[Robert Goldman <rpgoldman@sift.info>]

I have a @car category that I use to keep track of things I might want
to do when out in the car.  Getting the agenda view *almost* works for
this.  But often an item here indicates that I should visit some store,
and underneath the item is a list of things to purchase.  The agenda
view, of course, suppresses that list.  This means that printing out (or
pushing to my palm) the agenda view isn't really what I want.  I'd
really like to have the subtree below the matching items (because I know
the subtree is always trivial).

I *think* I should be able to do this with a custom agenda command,
using sparse trees, but I'm having a couple of problems figuring this out:

1.  I don't really want a sparse tree, because I don't want anything
"upstream" of the selected items.

2.  I want to force the matches to be expanded.

3.  I want to match on a tag (@car) *and* on a TODO tag "TODO".  I may
be missing something, but I don't see any obvious conjunctive matching
command in the sparse tree or agenda codes.

Is there any existing way to do this, or should I start rooting around
in the code?

thanks!
Robert