Yes, you may need to purchase extra parts or accessories depending on your particular model. It is important to consider any additional purchases when shopping to customize and maximize the performance of your RC buggy. To adjust the speed settings of your RC buggy, you will need to read through the user manual of your model. This will provide you with all the necessary instructions and details on adjusting the speed settings. In some cases, there may also be a speed controller or remote control device that allows you to control and adjust the speed of your car as needed.