Abstract This work presents the design of a modular educational demonstrator that aims to enhance the learning experience of engineering technology students by incorporating hands-on learning activities in STEM Education. The students will be required to design and assemble a modular remote-controlled hydraulic vehicle to achieve various tasks. These tasks include a sprint race, a mountain climb, path following, and obstacle avoidance. The proposed design embodies a small vehicle chassis comprising modular hydrostatic transmission. Previously designed educational demonstrators lacked the option for students to customize various components and evaluate the system's performance based on their design decisions. The modifications made to this demonstrator allow the students to design and experiment with different component sizing and connections, resulting in a hands-on tool that can showcase the implementation of their calculated designs in a real-world setting. This demonstrator utilizes an open chassis design to allow interchangeability and speculation during testing and operation. All the hydraulic and electric components are mounted to the top of the chassis, allowing students to observe how the individual components operate. The vehicle is electrically powered using a 12V DC motor that acts as the prime mover of the hydrostatic transmission. The involved hydraulic units, i.e., pump and motor, are interchangeable, where they have counterparts with different ports, shaft sizes, and dimensions but different displacements. Thus, replacing the pump and motor with their counterparts provides various pressure and flow to the hydraulic system, thus achieving different output maximum speeds. The controller allows the operator to control the vehicle's speed and direction via a proportional control valve and a servo motor. The proportional control valve regulates the flow entering the circuit, which varies the vehicle's speed. The valve can be actuated in three positions, allowing the operator to move forward, backward, and brake. An electrical servo motor is attached to the vehicle's front wheel to control the steering. The modular design increases the vehicle's utility as an educational instrument by allowing students to size components, implement them on the vehicle, and experience the functionality of their designs on a working demonstrator.