Mountain Pass doesn't let the second bidder know what the first person bid.
PS: I'm assuming "card bugs" here means "bugs with card shaped things"
The minimum bid you can make as second bidder is 1 higher than the first bid. This seems like enough information to me, but maybe it's better to display the first bid more prominently. It would certainly be helpful in >2p games (seeing what the highest bid is and who made it).