Too cold/snowy/rainy/etc. to ride or do much of anything else, I would echo what has already been said about sales items. A solid 15% or better on all clothing, parts & accessories would get me in to look around. Food may draw some but I wouldn't go somewhere for the grub--but if i am already in there looking at sale items I might be inclined to have a sandwich/burger/whatever and hang out a while. And the problem is when I hang out at a HD dealer my checkbook sometimes takes a hit. Isn't that what you dealers want?
Maybe give everyone entering your store that day a raffle ticket for a drawing at the end of the weeknd for a free service/something worthwhile.