Note that you can make something roughly similar to a track saw by throwing together your own saw guide. Cut about a foot off sheet of plywood so you can use the factory edge as a straight edge. Glue-and-screw that on top of another layer of plywood, with its straight edge set back from the lower layer's edge by a bit more than the distance from the edge of the saw's baseplate to the blade. After the glue has set, run the saw along the straight edge to cut the bottom layer to exactly match that measurement of the saw.
Now you can line up the newly cut edge of this jig exactly with the line you want to cut, clamp it in place, adjust the depth of cut, and once again use the top layer as an edge guide for the saw. It isn't as precise as a fully-guided saw, and it isn't zero-clearance on both sides of the cut as the track saws are --- but for most purposes it's more than good enough.
You can make this fancier by adding a right-angle stop at one end, T-square style, to make it easier to align.
The same concept works with routers too, if you want to cut a straight dado. Remember to think about direction of cut; you want to move the router from left to right, so the spin of the bit will tend to push it more rightly against the reference edge rather than pull it away. If you have a fresh right-angle piece on the router jig, your first pass can cut the dado into that as well, giving you a clear view of exactly what will be cut, which can help reassure you that you really do have the jig in the right place.
(Too many words, but Stack Exchange frowns on just posting pointers to articles elsewhere. However, a bit of websearching will find nice illustrations of exactly what I'm describing.)
This can also be turned into a poor man's panel saw, by the way: Set up braces to support the panel, attach this guide at the right place, clamp, crosscut or rip. One of the woodworking magazines had a cute set of wall-mounted supports for exactly that purpose in a tips column some time in the past few years.)