This is interesting: On the grill http://findarticles.com/p/articles/mi_qa3819/is_199908/ai_n8863229
In the toaster http://ipmsstockholm.org/magazine/2002/08/stuff_eng_tech_moulding_canopies.htm There are tons of articles if you google vacuum formed canopies http://www.largescaleplanes.com/tips/RatoMarczak/jigs/vacuumform.html