Mezue ahịrịokwu na-esonụ: Maka 1954 Spanish Grand Prix Rosier banyere Maserati 250F ọhụrụ, wee kwụsị na ọnọdụ nke asaa. Na Rosier laghachiri ịbanye naanị otu ụgbọ ala maka onwe ya. Ọ lara ezumike nká na Monaco wee mechaa nke itoolu na Belgium na Netherlands. N'ihi na Rosier ọzọ banyere Maserati. Ọ malitere oge ahụ site na ịla ezumike nká na Monaco tupu ọ gwụchaa nke asatọ na
Belgium na nke isii na France. Mgbe ọ malitere na 27th na Britain, Rosier lara ezumike nká na okirikiri iri abụọ na atọ mgbe ọkụ eletrik ya dara. Nnukwu Prix nke German nke 1956, ebe Rosier kwụsịrị nke ise siri ike, gosipụtara na ọ bụ Nnukwu Prix ikpeazụ nke Ecurie Rosier n'ihi na Louis Rosier nwụrụ n'ihi mmerụ ahụ ọ tara n'ihe mberede na Montlhéry track, na ndịda Paris, France na 7 Ọktọba 1956.