wheel bearing would be my guess. as they go bad the noise gets pretty loud, like being in a wind tunnel. as it goes bad u will get a vibration also. main relay is my guess also. in the heat the contacts lose their connection. the main relay u can do yourself. it signals the fuel pump. as the relay goes bad u will get more frequent no starts especially after short trips ie. leave home, go to a store for a quick item, leave and it wont start. wait awhile longer then it starts.