Keep track of your Design Points throughout this entire process.
1: Select a chassis. This is going to be either Anthroform, Medium (big dwarfs, humans, elves, most orks) or Anthroform, Large (big orks, trolls).
2: Select a power source. Most types have designs for the anthroforms: Battery, Diesel, Electric Fuel Cell, Gasoline, and Methane. Sorry, you can't have a nuclear- or sail-powered anthroform.
This gives you your starting attributes (speed, handling, load, etc.) and your maximum attributes.
4: Adjust your attributes to where you want them.
5: Select standard (built-in) design options and vehicle modifications. Some of these are mutually exclusive; several of them will increase or decrease the limits on your Speed, Handling, and Load attributes without actually altering those attributes. IF LIMITS=ADJUSTED, THEN GOTO 4.
6: Add in any other modifications you might want.
7: Determine final cost. This is Design Point Total x Mark-Up Factor (found on your chassis table), rounded up to the nearest nuyen.
8: Fuck Shit Up.