Pay attention to the scale. The most common scale is 1/8 and 1/10. The larger the denominator, the smaller machine. The model is 1/8, respectively, will be larger than that of 1/10. Buying a car for a child, stop your choice on these scales. Produced and larger cars, 1/5 scale. This is quite a large car, often with a petrol engine. Quite often you can find smaller models, 1/12, and even 1/16 1/18. They are in demand mostly among collectors.
What type of engine do you prefer? It can be both electric and internal combustion. Children is the motor, and to gift an adult can be any. The internal combustion engine provides more power than electric. Also ask where to buy fuel for this model. Typically, RC cars fuels based on methanol. Fuel is pretty expensive, up to 2 thousand rubles per 4 L.
Each type of engine has its pros and cons. The main drawback of the motor that movement of the model depends heavily on charging the battery. 15-20 minutes — the limit for a single charge. However, the machine motor is quiet and does not pollute the environment.
Inspect the chassis. They are of several types, depending on the purpose of the car. Chassis type "Formula-1" on a good smooth surface. This type of machine can give a lot of speed. For riding on rough terrain better suited chassis "Trucks" or "Monster."
Find out as much possible about the management system model. Some cars can run barely out of the box. But there are models that need to be collected. It is preferable, of course, "ready to eat", but they can be very different in price.
Ask what kind of battery runs the model. It all depends on the purpose for which the purchased model. For serious competition it is better to choose battery more expensive, but more powerful. For game or racing home in principle you can use any. The main thing is to make them easy to buy.
Inspect the contents. Regardless of what type of engine you choose, the car should be the chassis, body, speed controller. For machines with motor, battery and charger. For a vehicle with internal combustion engine - a fuel bottle for refueling, a device for glow plug starter and 4 batteries. If the model belongs to the class of "Ready To Run", then all you need is already there and put in place. But some models need to bring to mind or even to assemble from parts that you can buy separately.
The car body can be bought separately, as well, and the rest of the details.