Ground Vehicles

Tech building techniques
Basic stuff: Generally, symmetry means that the vehicle handles well, and doesn't constantly want to turn. Building wide helps with turning. Building long and narrow reduces turning ability.

Getting stuck
At some point in your tech building career, your tech is going to get stuck on the land. Typically, this happens when the vehicle becomes too wide or too long for the strength of the wheels. And this is exacerbated by extra weight on the vehicle.

Vehicles get stuck in two main ways: Getting stuck on a hill or ridge or in a valley.

Ridge/Hill stuck
Dealing with the hill and ridge issue is relatively simple. Put wheels in the middle/centreline. That way, there's some driving gear to keep things moving, and not scraping on the ground. If you have the R&D pack and have unlocked the GSO Wheel Hub put some of these in the centre. This will help carry the load, and stop you getting stuck.

Catamaran
If you don't have the pack, or haven't unlocked it, or you're dealing with bigger techs and the Hub Wheel is no use to you, you can build a catamaran type of base:

Some exaples of non-sticking vehicles:

Valley Sticking
Now this is a little different. most of us expect our tech to get stuck if there's stuff sticking out on the corners to get stuck.

But what's up with this:

That's a tech that's 100% wheel. How can it possibly get stuck? Well, when something with multiple wheels hits a slope, the wheels that contact the slope have to take the entire weight of the vehicle. Which means that they will likely stick if you need a whole lot of wheels to make your vehicle go.

There is no real solution to this problem, it's a matter of scale. You can fix it to a degree, by using bigger and stronger wheels. But you will re-encounter the problem again when your tech develops to the size that it needs a stack of the larger wheels.

So the only real way to avoid encountering this problem is to keep your tech small enough, that it does not need massive numbers of a given wheel to let it move.

One method that can help a little is simulate tank tracks, by raising the front wheels like this:

What this does is let more wheels take the weight when you hit the slope, thus helping you to not stick. It also has the side effect of improving the turning, by shortening the wheel base in contact with the ground, but still having the wheels for hill climbing and redundancy.