OK ... now I'm glad I didn't cycle to Yosemite this past July like I was originally intending!! I've never heard of a bear breaking into a car in the Canadian Rockies, and the information pamphlet recommends leaving food in the cars. However, I think you're actually supposed leave it in the trunk.

http://www.pc.gc.ca/docs/v-g/oursnoi...ar/page6_e.asp

"Stash your trash! Garbage should be placed in the park's bear-proof garbage containers. If you store garbage at your site, keep it in a vehicle or hard-sided trailer. Keep your camping equipment, tent and tent-trailer clean and free of food odours."