Ok well I'm bored so I'll bite.
Unless you have a track car and not a daily then all you can really do is gut the interior.
If you want you can remove the a/c system but that's really up 2 you.
For low cost mods I would suggest you seriously spend the first few dollars to maintain the car.
For a few bucks you can get anyone of the following.
1. Seafoam (many good uses)
2. Oil change (use along with seafoam to help clean out the system)
3. Diff oil change (assuming you have a vlsd if not just wait till you get a diff)
4. Check your pads and rotors (if you need to replace spend the extra couple dollars and flush the brake lines)
5. Check p.s. fluid, clutch master and coolant
6. Flush out rad if needed
7. Replace belts
8. Degrease engine and engine bay
This is all for now. No point in doing mods to a car or motor that won't last.
Crawl before you run and oh yeah Look here for more good info
Google