As to my knowledge he is very tough when on tour. The only way to get him seems to be when he is doing a charity golf tournament. Or you will have a lot of luck.
Bob Seger is not a very easy autograph in person and doesn't like people who ask and he is aware of ebay and has been doing this for 40 years so he is a very jaded and not a nice person the few times I've tried. Good luck!