Go and have a chat with the parts guy at a car dealership. Bring measuring tools, and know what length bolt you need. M12x1.0 is used for flywheel bolts a lot, and other high strength "special" bolt locations.
It's pretty much a non-preferred standard size of thread, so it won't be hardware store stuff.
Tried a NAPA store?
Acklands Grainger? They may want you to have an account, if you call them on the phone, but like as not will sell for cash in person.
Look under fasteners in the phone book, for places like The Bolt Store, or Nut's and Bolts. (two outfits in Edmonton, from memory)
Phone some of the suppliers you find, and talk to a counterman. Most of these places are little beyond the technology level of having decent stock records, and few if any have their full stock online. Gotta talk to them. Need to be able to tell them diameter, pitch, length, head style wanted, etc.
Good luck!
Cheers
Trev