Oh, the poor wee bairn...
I have no idea how tiny your repair budget is-but is it possible to replace the gas tank entirely? That should do wonders for the rust in the fuel. Also, it looks like you might need to replace a few of those body areas entirely-if you forgo the cost of replacement panels you can always cut back to the unrusted metal and bridge the gaps with a few layers of fiberglass(at least on the areas not subject to critical loads!)
I love the classic looks of your Justy-I have no idea what your Cd is but I honestly can't think of any Aero mods that wouldn't ruin the lines. I suppose you could delete the passenger-side mirror and fashion an underflow tray for the body. The grill looks pretty minimal as is, a block might actually be overkill at this point. Some transparent headlight covers might help a little, but you stated you were on a budget...
And for what it's worth, my '93 Festiva has a faded red backside, a primer grey front and a (recently replaced) white drivers-side door. Oddly enough, I haven't has a single break-in so far!
