We outline our experiences with hidden and unsignposted learning by us and by our students arising from a team-based project activity in a 3rd-year undergraduate engineering module in the general Mechatronics area. We discuss the hidden learning achieved in areas such as team communications, team management, problem-solving skills, and communication through the media of student-produced video and presentations, as well as technical engineering reports. We describe the enablement of student reflection on their learning and its benefits and use these reflections to evidence various aspects of their learning. The work is situated within the literature on innovations and quality of STEM education.