Yes you can, you can either go to a junk yard and pull the unit out of an other E36, or you can get a universal set up for fairly cheap. I would not however buy an Ebay key blank, even if it's cheap you have to remember that you will also have to pay some one to cut it (which might require you to send the original off somewhere), and even after that you will still need to source an EWS II transponder chip (which is VIN specific) and can only be ordered from the dealer, so you're much better off to just go and pay the dealer $60 and get every thing taken care of.