What I would like to see in OO is some 4-car EMUS, for the post-war period, particularly suburban non-gangwayed types. It's all very well producing 2-car units (like the 2Bil, 2Hal, 2EPB and 2HAP), but if I want to run the trains I went to school on, then the trains I commuted to work on, on my layout I've got to find 4Sub, 4EPB (two types), Networkers, ... none of which is available RTR.