my car had the same problem. I just did a permutation and combination for it..My care just had 6 numbers from 1,2 to ...6, and the code was 4 digits.
So i tried codes starting ...
1111,1112,1113,1114,1115,1116
1121,1122,1123,1124,1125,1126
etc..
and finally broke the code in 54th attempt which was good and it took me 15 mins...worth a try...
VijayG, February 2007