Warning: this is just a test with very questinable info

"If you wanna do yourself a favor, use this as a guide: 1. Make it steer, 2. Make it handle, 3. Make it fast You will get the most of of your money, and always have a fun truck that you dont mind upgrading. Do it backwards and you will hate the truck until you do it all."

1. Stock steering on E-Maxx is very weak, get a kit with ball-bearings and a stronger saver, like Pro-Line Steering Kit Maxx (to fit in the E-Maxx the chassis need some cutting).

2. For 6v power to your servos, use a good Battery Eliminator Circuit (BEC) instead of a separate Receiver Battery Pack. It is less weight and you don't notice anything and don't need to charge it. Now go for stronger servo if you need it.

3. Batteries doesn't need to be waterproofed (the volt is too low). Heat-shrinking might trap water and promote rusting.

4. Aluminum upgrades bend and break easily, and steel CVDs make it heavy. Make it light with accessories and consider LiPoly instead.

5. Put some medium-soft foam stuff behind the front and rear skidplate and they will be almost invincible but still doing their job, and with virtually no extra wheight. Foam I mean for example the stuff aluminum pivot balls come in.

6. Keep the Stock Traxxas TQ3, it is the only radio I know that has a big switch for shifting. This makes it more fun to shift to second and easier to know which gear you're in. Better gameplay.

7. Buy rechargable NiMh batteries for your transmitter. They may be lower rating volt then regular dry alkalines but rechargable batteries volt doesn't drop under load so it works fine. Then open it up and solder a female plug to the wires thats connected to the + and - on the battery box like this. Warning: Be careful with static discharge and don't bend the wires too much then they will break at the soldering points.
Update: Use high-volt low resistance rated quality nimh batteries (such that can be fast-charged). I bought some GP2300 at a computer store and have to charge them every time I've been out or the range is not good. Could be other problems, I use non-recharge NiOx batteries for now.