First - Do your research. There are many decades of projects, countless hours, and (I shudder to think about) cash spent going down much the same path as you are thinking about going down, available in the archives. All you need to do is click on the magnifying glass tool in the upper right of the page and choose a variety of keywords.
Use these previous posts wisely. This forum and some of these players go back to when there were still vacuum tubes in controllers (not really). Much of this tech has been explored and abandoned (for one reason or another) already. The archives are a fantastic learning tool that doesn’t cost you a thing (yet). Use the old stuff so you can see where this all came from.
Then - Skip to the end of the book to see the stuff everybody is playing with today. Here is a good example of the richness that can be found in the forums.
The problem is that you are starting with a pre <2004 car as your base. Paging through the classifieds you can find a wide range of cars and many think they can be bought cheap, fixed up, end up sinking a ton of money into them and still find them not quite up what they wanted. They usually sell them to the next guy and look for a later model car and start over or wander away from the whole e-car thing completely.
If you are a brand new owner of your 2003 you may not know this yet. The early cars have quite a few issues. If you have owned your car for a while you may already know about some/all of these issues and may have already corrected them.
- The brakes are horrible.
- Suspension is like a dump truck
- Steering is from same dump truck
- Motor selection is limited
- Gear ratio is set more/less for street (depending on your build this may/may not be bad)
- Electrical system is marginal
- Battery space is limited
- Parts getting difficult to find
- Charger may need to be upgraded for Lithium. (Is yours yellow/black)
This all being said, Most of the above can be dealt with, and many are quite happy with their early cars. It all depends on what your goals are.
Or use this car as a test bed for tinkering and keep your eye out for a deal on a 2006 car to build your hotrod. Most of the above issues have been dealt with.
Then, you need to decide what you want your car to be. Your description “get the max out of my car” is quite typical of how most of these projects start. Yes - quite a bit can be done. In the end you will still have a 20 year old car that you put a ton of cash into that you will never get back out. If you are fine with that, then proceed.
If you can do most of the work yourself that is a bonus. It gets real expensive if you need outside help to do the work. Some of these flipper guys charge quite a bit to polish your car for you and some guys out there actually make a living from it.
Here is something on your Leaf Pack. Make sure they will suit your needs.
I may have more to add later… We are just getting started.