factory code needed for stock stereo.?

i have a 1999 mitsubushi montero sport psecial edition suv. not the 4wheel version. im buying it off my brother in law but need the factory code to enter it to use the stereo. i guess he had to replace the battery. this is not a stolen vehicle. can anyone help me? the dealership wants me to bring it in and charge me 75 bucks but i live 4 hrs away from the nearest one. besides i think its ridiculous to pay money to get a dumb code just to use the radio. thanks!