We haven't actually built our car yet, so I'm not sure if this would actually work or not, but it seems like it - you could make the extension bar actually like a rectangle with only 3 sides, so that it attaches to the outer side of each mousetrap and forms a sort of loop. That way, even if only one mousetrap is set, the connection is such that they both move together. Not sure if I'm being clear or not, but that's the idea - tell me if it works!
2015 events: WIDI, Protein Modeling, Geomapping, Chem Lab
2014 events: WIDI, Geomapping, Materials Science, Food Science
2013 events: WIDI, Mousetrap Vehicle, Heredity, Food Science, Metric Mastery
Best ever place: Nationals, 3rd in WIDI