Instructions
Look at the car you're interested in at a store before buying the car. Many 1:8 scale vehicles differ in size dramatically from manufacturer to manufacturer.
Plan your budget in advance and stick to it when shopping around. Some of the cars and trucks in this scale are fairly expensive, but you can still find cheaper options available.
Choose the type of speed you need out of the car. While some cars can reach speeds of 50-60 miles per hour, other vehicles are much smaller.
Pick between a car, truck or monster truck. Each vehicle has different advantages and disadvantaged, but you can learn more at your local hobby store.
Decide if you prefer a gas or nitro powered car or an electric car. Both are available in this scale, but electric cars require batteries rather than fuel to run.
Examine different stores to look at a large variety of colors and paint schemes. There are hundreds of different styles out there so you can find one that you like.
Ask for advice from experienced racers and car enthusiasts, especially those who race the 1:8 scale cars. This will help you learn what to look for and what to avoid.