hey, warwick is also my firm and i was able to switch courses. I emailed warwick admissions with my details and why I wanted to change courses, they took around 1-2 weeks to respond but they allowed me to switch. Engineering will be far more popular than the course I changed to so that may affect whether they allow you too. But if the entry requirements are similar then they should definitely reply. students also change courses once they have started in September so i wouldn't worry!