Q. We considered Ausubel-Milgrom ascending proxy auction, which y sell as best of both worlds: under full information, prot-target equilibrium coincide with bidder-optimal points in core (like in Bernheim and Whinston); and when goods are substitutes, truthful bidding is an equilibrium even with private information, leading to an ancient outcome as in Vickrey auction. However, we haven't been able to say much on theoretical side about private information combined with complementarities. (Finally, for variety, we wrapped up with some analysis of wars of attrition and a generalized all-pay setting.) So, where do we go from here?